Grafic Glitsches

Help
1

Hi everyone,

I’m hoping someone can help me troubleshoot a weird display issue I’ve been having on KDE Neon.

The Setup:

  • OS: KDE Neon (fully updated)

  • Hardware: Laptop connected via USB-C/2x DisplayPort, 1x HDMI to 3 external monitors.

  • Context: This started happening after I used a different docking station at my office. Now that I’m back in my home office, the issue appered.

The Problem: I am seeing graphical glitches (pixelated horizontal distortion/stretching to the right) but only on the rightmost monitor of my 3-screen setup.

photo_2025-12-19_09-40-26
photo_2025-12-19_09-40-26720×1280 123 KB

The Strange Part (The “Overlay” Clue): The glitch seems to be tied to the compositor or window management:

  • As soon as I drag a window to the edge of the screen to trigger the tiling/snap overlay (the gray area that shows where the window will dock), the glitch completely disappears and the screen looks perfect.

  • The moment I release the window and the gray overlay disappears, the pixelated distortion returns immediately.

What I’ve tried so far:

  • Full system update.

  • Multiple restarts.

  • Switching between different USB-C ports on the laptop.

  • Since the glitch disappears when a system UI overlay is active, I suspect this is a software/compositor issue rather than a hardware/cable defect.

  • Its working flawless on a Windows Device with all 3 Displays (So i can rule out any Hardware errors)

Has anyone encountered something similar? Could it be a cached display configuration from the other dock that is causing a conflict?

Thanks in advance for any ideas!

System

KDE neon User Edition
KDE-Plasma-Version: 6.5.4
KDE-Frameworks-Version: 6.21.0
Qt-Version: 6.10.1
Kernel-Version: 6.14.0-37-generic (64-bit)
Grafik-Plattform: Wayland
Prozessor: 12 × 13th Gen Intel® Core™ i7-1365U
Memory: 32 GiB of RAM (30,7 GiB usable)
Graficprozessor: Intel® Iris® Xe Graphics
Dell Inc. Latitude 7640

Displays

card1-DP-3

Block 0, Base EDID:
EDID Structure Version & Revision: 1.3
Vendor & Product Identification:
Manufacturer: BNQ
Model: 30933
Serial Number: 21573 (0x00005445)
Made in: week 36 of 2017
Basic Display Parameters & Features:
Digital display
Maximum image size: 60 cm x 34 cm
Gamma: 2.20
DPMS levels: Off
RGB color display
Default (sRGB) color space is primary color space
First detailed timing is the preferred timing
Color Characteristics:
Red : 0.6425, 0.3457
Green: 0.3212, 0.6259
Blue : 0.1503, 0.0517
White: 0.3134, 0.3291
Established Timings I & II:
IBM : 720x400 70.081663 Hz 9:5 31.467 kHz 28.320000 MHz
DMT 0x04: 640x480 59.940476 Hz 4:3 31.469 kHz 25.175000 MHz
DMT 0x06: 640x480 75.000000 Hz 4:3 37.500 kHz 31.500000 MHz
DMT 0x09: 800x600 60.316541 Hz 4:3 37.879 kHz 40.000000 MHz
DMT 0x0b: 800x600 75.000000 Hz 4:3 46.875 kHz 49.500000 MHz
Apple : 832x624 74.551266 Hz 4:3 49.726 kHz 57.284000 MHz
DMT 0x10: 1024x768 60.003840 Hz 4:3 48.363 kHz 65.000000 MHz
DMT 0x12: 1024x768 75.028582 Hz 4:3 60.023 kHz 78.750000 MHz
DMT 0x24: 1280x1024 75.024675 Hz 5:4 79.976 kHz 135.000000 MHz
Apple : 1152x870 75.061550 Hz 192:145 68.681 kHz 100.000000 MHz
Standard Timings:
DMT 0x23: 1280x1024 60.019740 Hz 5:4 63.981 kHz 108.000000 MHz
DMT 0x55: 1280x720 60.000000 Hz 16:9 45.000 kHz 74.250000 MHz
DMT 0x1c: 1280x800 59.810326 Hz 16:10 49.702 kHz 83.500000 MHz
DMT 0x53: 1600x900 60.000000 Hz 16:9 60.000 kHz 108.000000 MHz (RB)
DMT 0x3a: 1680x1050 59.954250 Hz 16:10 65.290 kHz 146.250000 MHz
DMT 0x52: 1920x1080 60.000000 Hz 16:9 67.500 kHz 148.500000 MHz
Detailed Timing Descriptors:
DTD 1: 1920x1080 60.000000 Hz 16:9 67.500 kHz 148.500000 MHz (598 mm x 336 mm)
Hfront 88 Hsync 44 Hback 148 Hpol P
Vfront 4 Vsync 5 Vback 36 Vpol P
Display Product Serial Number: ‘79H03108019’
Display Product Name: ‘BenQ GL2760’
Extension blocks: 1
Checksum: 0x96

Block 1, CTA-861 Extension Block:
Revision: 3
Underscans IT Video Formats by default
Basic audio support
Supports YCbCr 4:4:4
Supports YCbCr 4:2:2
Native detailed modes: 1
Video Data Block:
VIC 16: 1920x1080 60.000000 Hz 16:9 67.500 kHz 148.500000 MHz (native)
VIC 31: 1920x1080 50.000000 Hz 16:9 56.250 kHz 148.500000 MHz
VIC 1: 640x480 59.940476 Hz 4:3 31.469 kHz 25.175000 MHz
VIC 1: 640x480 59.940476 Hz 4:3 31.469 kHz 25.175000 MHz
VIC 4: 1280x720 60.000000 Hz 16:9 45.000 kHz 74.250000 MHz
VIC 19: 1280x720 50.000000 Hz 16:9 37.500 kHz 74.250000 MHz
VIC 3: 720x480 59.940060 Hz 16:9 31.469 kHz 27.000000 MHz
VIC 18: 720x576 50.000000 Hz 16:9 31.250 kHz 27.000000 MHz
VIC 1: 640x480 59.940476 Hz 4:3 31.469 kHz 25.175000 MHz
VIC 1: 640x480 59.940476 Hz 4:3 31.469 kHz 25.175000 MHz
VIC 1: 640x480 59.940476 Hz 4:3 31.469 kHz 25.175000 MHz
VIC 1: 640x480 59.940476 Hz 4:3 31.469 kHz 25.175000 MHz
VIC 1: 640x480 59.940476 Hz 4:3 31.469 kHz 25.175000 MHz
VIC 17: 720x576 50.000000 Hz 4:3 31.250 kHz 27.000000 MHz
VIC 2: 720x480 59.940060 Hz 4:3 31.469 kHz 27.000000 MHz
Audio Data Block:
Linear PCM:
Max channels: 2
Supported sample rates (kHz): 48 44.1 32
Supported sample sizes (bits): 24 20 16
Speaker Allocation Data Block:
FL/FR - Front Left/Right
Detailed Timing Descriptors:
DTD 2: 1920x1080 60.000000 Hz 16:9 67.500 kHz 148.500000 MHz (598 mm x 336 mm)
Hfront 88 Hsync 44 Hback 148 Hpol P
Vfront 4 Vsync 5 Vback 36 Vpol P
DTD 3: 1920x540 60.053381 Hz 32:9 33.750 kHz 74.250000 MHz (598 mm x 336 mm)
Hfront 88 Hsync 44 Hback 148 Hpol P
Vfront 2 Vsync 5 Vback 15 Vpol P
DTD 4: 1280x720 60.000000 Hz 16:9 45.000 kHz 74.250000 MHz (598 mm x 336 mm)
Hfront 110 Hsync 40 Hback 220 Hpol P
Vfront 5 Vsync 5 Vback 20 Vpol P
DTD 5: 720x480 59.940060 Hz 3:2 31.469 kHz 27.000000 MHz (598 mm x 336 mm)
Hfront 16 Hsync 62 Hback 60 Hpol N
Vfront 9 Vsync 6 Vback 30 Vpol N
Checksum: 0x12

Failures:

Block 0, Base EDID:
Display Range Limits: ‘Bare Limits’ is not allowed for EDID < 1.4.
EDID conformity: FAIL

card1-DP-4

Block 0, Base EDID:
EDID Structure Version & Revision: 1.4
Vendor & Product Identification:
Manufacturer: GSM
Model: 30471
Serial Number: 152315 (0x000252fb)
Made in: week 3 of 2021
Basic Display Parameters & Features:
Digital display
Bits per primary color channel: 10
DisplayPort interface
Maximum image size: 60 cm x 34 cm
Gamma: 2.20
DPMS levels: Standby
Supported color formats: RGB 4:4:4, YCrCb 4:4:4, YCrCb 4:2:2
Default (sRGB) color space is primary color space
First detailed timing includes the native pixel format and preferred refresh rate
Color Characteristics:
Red : 0.6796, 0.3154
Green: 0.2802, 0.6738
Blue : 0.1523, 0.0498
White: 0.3125, 0.3291
Established Timings I & II:
DMT 0x04: 640x480 59.940476 Hz 4:3 31.469 kHz 25.175000 MHz
DMT 0x09: 800x600 60.316541 Hz 4:3 37.879 kHz 40.000000 MHz
DMT 0x10: 1024x768 60.003840 Hz 4:3 48.363 kHz 65.000000 MHz
Standard Timings:
GTF : 1152x864 60.000000 Hz 4:3 53.700 kHz 81.624000 MHz
DMT 0x23: 1280x1024 60.019740 Hz 5:4 63.981 kHz 108.000000 MHz
DMT 0x55: 1280x720 60.000000 Hz 16:9 45.000 kHz 74.250000 MHz
DMT 0x53: 1600x900 60.000000 Hz 16:9 60.000 kHz 108.000000 MHz (RB)
DMT 0x52: 1920x1080 60.000000 Hz 16:9 67.500 kHz 148.500000 MHz
DMT 0x1c: 1280x800 59.810326 Hz 16:10 49.702 kHz 83.500000 MHz
Detailed Timing Descriptors:
DTD 1: 3840x2160 59.996625 Hz 16:9 133.312 kHz 533.250000 MHz (600 mm x 340 mm)
Hfront 48 Hsync 32 Hback 80 Hpol P
Vfront 54 Vsync 5 Vback 3 Vpol N
DTD 2: 3840x2160 30.000000 Hz 16:9 66.660 kHz 266.640000 MHz (600 mm x 340 mm)
Hfront 8 Hsync 144 Hback 8 Hpol P
Vfront 54 Vsync 5 Vback 3 Vpol N
Display Range Limits:
Monitor ranges (Range Limits Only): 56-61 Hz V, 30-135 kHz H, max dotclock 560 MHz
Display Product Name: ‘LG HDR 4K’
Extension blocks: 1
Checksum: 0x1a

Block 1, CTA-861 Extension Block:
Revision: 3
Basic audio support
Supports YCbCr 4:4:4
Supports YCbCr 4:2:2
Native detailed modes: 1
Video Data Block:
VIC 16: 1920x1080 60.000000 Hz 16:9 67.500 kHz 148.500000 MHz (native)
VIC 4: 1280x720 60.000000 Hz 16:9 45.000 kHz 74.250000 MHz
VIC 3: 720x480 59.940060 Hz 16:9 31.469 kHz 27.000000 MHz
VIC 1: 640x480 59.940476 Hz 4:3 31.469 kHz 25.175000 MHz
Audio Data Block:
Linear PCM:
Max channels: 2
Supported sample rates (kHz): 48 44.1 32
Supported sample sizes (bits): 24 20 16
Speaker Allocation Data Block:
FL/FR - Front Left/Right
Colorimetry Data Block:
BT2020YCC
BT2020RGB
HDR Static Metadata Data Block:
Electro optical transfer functions:
Traditional gamma - SDR luminance range
SMPTE ST2084
Supported static metadata descriptors:
Static metadata type 1
Desired content max luminance: 96 (400.000 cd/m^2)
Desired content max frame-average luminance: 85 (315.196 cd/m^2)
Desired content min luminance: 80 (0.394 cd/m^2)
Detailed Timing Descriptors:
DTD 3: 1920x1080 60.000000 Hz 16:9 67.500 kHz 148.500000 MHz (600 mm x 340 mm)
Hfront 88 Hsync 44 Hback 148 Hpol P
Vfront 4 Vsync 5 Vback 36 Vpol P
DTD 4: 2560x1440 59.950550 Hz 16:9 88.787 kHz 241.500000 MHz (600 mm x 340 mm)
Hfront 48 Hsync 32 Hback 80 Hpol P
Vfront 3 Vsync 5 Vback 33 Vpol N
Checksum: 0x1e

EDID conformity: PASS

card1-DP-5

Block 0, Base EDID:
EDID Structure Version & Revision: 1.4
Vendor & Product Identification:
Manufacturer: BNQ
Model: 30933
Serial Number: 21573 (0x00005445)
Made in: week 36 of 2017
Basic Display Parameters & Features:
Digital display
Color depth is undefined
Digital interface is not defined
Maximum image size: 60 cm x 34 cm
Gamma: 2.20
DPMS levels: Off
Supported color formats: RGB 4:4:4, YCrCb 4:4:4, YCrCb 4:2:2
First detailed timing includes the native pixel format and preferred refresh rate
Color Characteristics:
Red : 0.6425, 0.3457
Green: 0.3212, 0.6259
Blue : 0.1503, 0.0517
White: 0.3134, 0.3291
Established Timings I & II:
IBM : 720x400 70.081663 Hz 9:5 31.467 kHz 28.320000 MHz
DMT 0x04: 640x480 59.940476 Hz 4:3 31.469 kHz 25.175000 MHz
DMT 0x06: 640x480 75.000000 Hz 4:3 37.500 kHz 31.500000 MHz
DMT 0x09: 800x600 60.316541 Hz 4:3 37.879 kHz 40.000000 MHz
DMT 0x0b: 800x600 75.000000 Hz 4:3 46.875 kHz 49.500000 MHz
Apple : 832x624 74.551266 Hz 4:3 49.726 kHz 57.284000 MHz
DMT 0x10: 1024x768 60.003840 Hz 4:3 48.363 kHz 65.000000 MHz
DMT 0x12: 1024x768 75.028582 Hz 4:3 60.023 kHz 78.750000 MHz
DMT 0x24: 1280x1024 75.024675 Hz 5:4 79.976 kHz 135.000000 MHz
Apple : 1152x870 75.061550 Hz 192:145 68.681 kHz 100.000000 MHz
Standard Timings:
DMT 0x23: 1280x1024 60.019740 Hz 5:4 63.981 kHz 108.000000 MHz
DMT 0x55: 1280x720 60.000000 Hz 16:9 45.000 kHz 74.250000 MHz
DMT 0x1c: 1280x800 59.810326 Hz 16:10 49.702 kHz 83.500000 MHz
DMT 0x53: 1600x900 60.000000 Hz 16:9 60.000 kHz 108.000000 MHz (RB)
DMT 0x3a: 1680x1050 59.954250 Hz 16:10 65.290 kHz 146.250000 MHz
DMT 0x52: 1920x1080 60.000000 Hz 16:9 67.500 kHz 148.500000 MHz
Detailed Timing Descriptors:
DTD 1: 1920x1080 60.000000 Hz 16:9 67.500 kHz 148.500000 MHz (598 mm x 336 mm)
Hfront 88 Hsync 44 Hback 148 Hpol P
Vfront 4 Vsync 5 Vback 36 Vpol P
Display Product Serial Number: ‘79H03118019’
Display Range Limits:
Monitor ranges (Range Limits Only): 50-76 Hz V, 30-83 kHz H, max dotclock 170 MHz
Display Product Name: ‘BenQ GL2760’
Extension blocks: 1
Checksum: 0x88

Block 1, CTA-861 Extension Block:
Revision: 3
Underscans IT Video Formats by default
Basic audio support
Supports YCbCr 4:4:4
Supports YCbCr 4:2:2
Native detailed modes: 1
Video Data Block:
VIC 16: 1920x1080 60.000000 Hz 16:9 67.500 kHz 148.500000 MHz (native)
VIC 31: 1920x1080 50.000000 Hz 16:9 56.250 kHz 148.500000 MHz
VIC 1: 640x480 59.940476 Hz 4:3 31.469 kHz 25.175000 MHz
VIC 1: 640x480 59.940476 Hz 4:3 31.469 kHz 25.175000 MHz
VIC 4: 1280x720 60.000000 Hz 16:9 45.000 kHz 74.250000 MHz
VIC 19: 1280x720 50.000000 Hz 16:9 37.500 kHz 74.250000 MHz
VIC 3: 720x480 59.940060 Hz 16:9 31.469 kHz 27.000000 MHz
VIC 18: 720x576 50.000000 Hz 16:9 31.250 kHz 27.000000 MHz
VIC 1: 640x480 59.940476 Hz 4:3 31.469 kHz 25.175000 MHz
VIC 1: 640x480 59.940476 Hz 4:3 31.469 kHz 25.175000 MHz
VIC 1: 640x480 59.940476 Hz 4:3 31.469 kHz 25.175000 MHz
VIC 1: 640x480 59.940476 Hz 4:3 31.469 kHz 25.175000 MHz
VIC 1: 640x480 59.940476 Hz 4:3 31.469 kHz 25.175000 MHz
VIC 17: 720x576 50.000000 Hz 4:3 31.250 kHz 27.000000 MHz
VIC 2: 720x480 59.940060 Hz 4:3 31.469 kHz 27.000000 MHz
Audio Data Block:
Linear PCM:
Max channels: 2
Supported sample rates (kHz): 48 44.1 32
Supported sample sizes (bits): 24 20 16
Speaker Allocation Data Block:
FL/FR - Front Left/Right
Detailed Timing Descriptors:
DTD 2: 1920x1080 60.000000 Hz 16:9 67.500 kHz 148.500000 MHz (598 mm x 336 mm)
Hfront 88 Hsync 44 Hback 148 Hpol P
Vfront 4 Vsync 5 Vback 36 Vpol P
DTD 3: 1920x540 60.053381 Hz 32:9 33.750 kHz 74.250000 MHz (598 mm x 336 mm)
Hfront 88 Hsync 44 Hback 148 Hpol P
Vfront 2 Vsync 5 Vback 15 Vpol P
DTD 4: 1280x720 60.000000 Hz 16:9 45.000 kHz 74.250000 MHz (598 mm x 336 mm)
Hfront 110 Hsync 40 Hback 220 Hpol P
Vfront 5 Vsync 5 Vback 20 Vpol P
DTD 5: 720x480 59.940060 Hz 3:2 31.469 kHz 27.000000 MHz (598 mm x 336 mm)
Hfront 16 Hsync 62 Hback 60 Hpol N
Vfront 9 Vsync 6 Vback 30 Vpol N
Checksum: 0x12

EDID conformity: PASS

card1-eDP-1

Block 0, Base EDID:
EDID Structure Version & Revision: 1.4
Vendor & Product Identification:
Manufacturer: LGD
Model: 1793
Made in: 2021
Basic Display Parameters & Features:
Digital display
Bits per primary color channel: 8
DisplayPort interface
Maximum image size: 34 cm x 22 cm
Gamma: 2.20
Supported color formats: RGB 4:4:4
First detailed timing includes the native pixel format and preferred refresh rate
Color Characteristics:
Red : 0.5947, 0.3701
Green: 0.3632, 0.5527
Blue : 0.1552, 0.1025
White: 0.3134, 0.3291
Established Timings I & II: none
Standard Timings: none
Detailed Timing Descriptors:
DTD 1: 1920x1200 60.000779 Hz 16:10 74.101 kHz 154.130000 MHz (345 mm x 215 mm)
Hfront 48 Hsync 32 Hback 80 Hpol P
Vfront 3 Vsync 6 Vback 26 Vpol N
DTD 2: 1920x1200 47.999066 Hz 16:10 59.279 kHz 123.300000 MHz (345 mm x 215 mm)
Hfront 48 Hsync 32 Hback 80 Hpol P
Vfront 3 Vsync 6 Vback 26 Vpol N
Alphanumeric Data String: ‘FNPN5�160WU1’
Checksum: 0xae

EDID conformity: PASS