Slow wifi on kernel 6.17 but not 6.11

My wifi connection became noticeably slow recently. To bisect the issue I’ve tried rolling back to kernel 6.11 and it works fine there but doesn’t work on the latest HWE (6.17.0-19-generic). I can see that the connection speed in the applet shows 54 mbps. Any idea what the issue might be? ChatGPT said it might be due to the interface country not being set correctly since the channel shows no HT - is that right? Here is my network info:

iw reg get; iw dev wlp0s20f3 info; sudo lshw -C network
global
country US: DFS-FCC
        (902 - 904 @ 2), (N/A, 30), (N/A)
        (904 - 920 @ 16), (N/A, 30), (N/A)
        (920 - 928 @ 8), (N/A, 30), (N/A)
        (2400 - 2472 @ 40), (N/A, 30), (N/A)
        (5150 - 5250 @ 80), (N/A, 23), (N/A), AUTO-BW
        (5250 - 5350 @ 80), (N/A, 24), (0 ms), DFS, AUTO-BW
        (5470 - 5730 @ 160), (N/A, 24), (0 ms), DFS
        (5730 - 5850 @ 80), (N/A, 30), (N/A), AUTO-BW
        (5850 - 5895 @ 40), (N/A, 27), (N/A), NO-OUTDOOR, AUTO-BW, PASSIVE-SCAN
        (5925 - 7125 @ 320), (N/A, 12), (N/A), NO-OUTDOOR, PASSIVE-SCAN
        (57240 - 71000 @ 2160), (N/A, 40), (N/A)

phy#0 (self-managed)
country US: DFS-UNSET
        (2402 - 2437 @ 40), (6, 22), (N/A), AUTO-BW, NO-HT40MINUS, NO-80MHZ, NO-160MHZ
        (2422 - 2462 @ 40), (6, 22), (N/A), AUTO-BW, NO-80MHZ, NO-160MHZ
        (2447 - 2482 @ 40), (6, 22), (N/A), AUTO-BW, NO-HT40PLUS, NO-80MHZ, NO-160MHZ
        (5170 - 5190 @ 160), (6, 22), (N/A), AUTO-BW, NO-HT40MINUS, NO-320MHZ
        (5190 - 5210 @ 160), (6, 22), (N/A), AUTO-BW, NO-HT40PLUS, NO-320MHZ
        (5210 - 5230 @ 160), (6, 22), (N/A), AUTO-BW, NO-HT40MINUS, NO-320MHZ
        (5230 - 5250 @ 160), (6, 22), (N/A), AUTO-BW, NO-HT40PLUS, NO-320MHZ
        (5250 - 5270 @ 160), (6, 22), (0 ms), DFS, AUTO-BW, IR-CONCURRENT, NO-HT40MINUS, NO-320MHZ
        (5270 - 5290 @ 160), (6, 22), (0 ms), DFS, AUTO-BW, IR-CONCURRENT, NO-HT40PLUS, NO-320MHZ
        (5290 - 5310 @ 160), (6, 22), (0 ms), DFS, AUTO-BW, IR-CONCURRENT, NO-HT40MINUS, NO-320MHZ
        (5310 - 5330 @ 160), (6, 22), (0 ms), DFS, AUTO-BW, IR-CONCURRENT, NO-HT40PLUS, NO-320MHZ
        (5490 - 5510 @ 160), (6, 22), (0 ms), DFS, AUTO-BW, IR-CONCURRENT, NO-HT40MINUS, NO-320MHZ
        (5510 - 5530 @ 160), (6, 22), (0 ms), DFS, AUTO-BW, IR-CONCURRENT, NO-HT40PLUS, NO-320MHZ
        (5530 - 5550 @ 160), (6, 22), (0 ms), DFS, AUTO-BW, IR-CONCURRENT, NO-HT40MINUS, NO-320MHZ
        (5550 - 5570 @ 160), (6, 22), (0 ms), DFS, AUTO-BW, IR-CONCURRENT, NO-HT40PLUS, NO-320MHZ
        (5570 - 5590 @ 160), (6, 22), (0 ms), DFS, AUTO-BW, IR-CONCURRENT, NO-HT40MINUS, NO-320MHZ
        (5590 - 5610 @ 160), (6, 22), (0 ms), DFS, AUTO-BW, IR-CONCURRENT, NO-HT40PLUS, NO-320MHZ
        (5610 - 5630 @ 160), (6, 22), (0 ms), DFS, AUTO-BW, IR-CONCURRENT, NO-HT40MINUS, NO-320MHZ
        (5630 - 5650 @ 160), (6, 22), (0 ms), DFS, AUTO-BW, IR-CONCURRENT, NO-HT40PLUS, NO-320MHZ
        (5650 - 5670 @ 80), (6, 22), (0 ms), DFS, AUTO-BW, IR-CONCURRENT, NO-HT40MINUS, NO-160MHZ, NO-320MHZ
        (5670 - 5690 @ 80), (6, 22), (0 ms), DFS, AUTO-BW, IR-CONCURRENT, NO-HT40PLUS, NO-160MHZ, NO-320MHZ
        (5690 - 5710 @ 80), (6, 22), (0 ms), DFS, AUTO-BW, IR-CONCURRENT, NO-HT40MINUS, NO-160MHZ, NO-320MHZ
        (5710 - 5730 @ 80), (6, 22), (0 ms), DFS, AUTO-BW, IR-CONCURRENT, NO-HT40PLUS, NO-160MHZ, NO-320MHZ
        (5735 - 5755 @ 80), (6, 22), (N/A), AUTO-BW, NO-HT40MINUS, NO-160MHZ, NO-320MHZ
        (5755 - 5775 @ 80), (6, 22), (N/A), AUTO-BW, NO-HT40PLUS, NO-160MHZ, NO-320MHZ
        (5775 - 5795 @ 80), (6, 22), (N/A), AUTO-BW, NO-HT40MINUS, NO-160MHZ, NO-320MHZ
        (5795 - 5815 @ 80), (6, 22), (N/A), AUTO-BW, NO-HT40PLUS, NO-160MHZ, NO-320MHZ
        (5815 - 5835 @ 40), (6, 22), (N/A), AUTO-BW, NO-HT40MINUS, NO-80MHZ, NO-160MHZ, NO-320MHZ
        (5945 - 7065 @ 160), (6, 22), (N/A), NO-OUTDOOR, AUTO-BW, IR-CONCURRENT, NO-320MHZ, PASSIVE-SCAN
        (7065 - 7105 @ 40), (6, 22), (N/A), NO-OUTDOOR, AUTO-BW, IR-CONCURRENT, NO-80MHZ, NO-160MHZ, NO-320MHZ, PASSIVE-SCAN
        (7105 - 7125 @ 20), (6, 22), (N/A), NO-OUTDOOR, AUTO-BW, IR-CONCURRENT, NO-HT40MINUS, NO-HT40PLUS, NO-80MHZ, NO-160MHZ, NO-320MHZ, PASSIVE-SCAN

Interface wlp0s20f3
        ifindex 5
        wdev 0x1
        addr ****
        ssid ****
        type managed
        wiphy 0
        channel 157 (5785 MHz), width: 20 MHz (no HT), center1: 5785 MHz
        txpower 22.00 dBm
        multicast TXQ:
                qsz-byt qsz-pkt flows   drops   marks   overlmt hashcol tx-bytes        tx-packets
                0       0       0       0       0       0       0       0               0
  *-network:0               
       description: Wireless interface
       product: Alder Lake-S PCH CNVi WiFi
       vendor: Intel Corporation
       physical id: 14.3
       bus info: pci@0000:00:14.3
       logical name: wlp0s20f3
       version: 11
       serial: ****
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress msix bus_master cap_list ethernet physical wireless
       configuration: broadcast=yes driver=iwlwifi driverversion=6.17.0-19-generic firmware=89.1a492d28.0 so-a0-gf-a0-89.uc ip=10.0.0.188 latency=0 link=yes multicast=yes wireless=IEEE 802.11
       resources: iomemory:400-3ff irq:18 memory:4012114000-4012117fff
  *-network
       description: Ethernet interface
       product: RTL8125 2.5GbE Controller
       vendor: Realtek Semiconductor Co., Ltd.
       physical id: 0
       bus info: pci@0000:03:00.0
       logical name: enp3s0
       version: 05
       serial: ****
       capacity: 1Gbit/s
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress msix vpd bus_master cap_list ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd 1000bt-fd autonegotiation
       configuration: autonegotiation=on broadcast=yes driver=r8169 driverversion=6.17.0-19-generic firmware=rtl8125b-2_0.0.2 07/13/20 latency=0 link=no multicast=yes port=twisted pair
       resources: irq:17 ioport:3000(size=256) memory:72200000-7220ffff memory:72210000-72213fff
  *-network:1
       description: Ethernet interface
       product: Ethernet Connection (17) I219-V
       vendor: Intel Corporation
       physical id: 1f.6
       bus info: pci@0000:00:1f.6
       logical name: enp0s31f6
       version: 11
       serial: ****
       capacity: 1Gbit/s
       width: 32 bits
       clock: 33MHz
       capabilities: pm msi bus_master cap_list ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd 1000bt-fd autonegotiation
       configuration: autonegotiation=on broadcast=yes driver=e1000e driverversion=6.17.0-19-generic firmware=2.3-4 latency=0 link=no multicast=yes port=twisted pair
       resources: irq:134 memory:72400000-7241ffff
  *-network
       description: Ethernet interface
       physical id: 5
       bus info: usb@1:5.2
       logical name: enxb04f13dc10d0
       serial: ****
       capacity: 1Gbit/s
       capabilities: ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd 1000bt 1000bt-fd autonegotiation
       configuration: autonegotiation=on broadcast=yes driver=r8152 driverversion=v1.12.13 duplex=half firmware=rtl8156b-2 v3 10/20/23 link=no multicast=yes port=MII

How can I fix this issue? I don’t want to revert to kernel 6.11 since the latest nvidia driver doesn’t seem to work there.

Here’s my full system info:

Operating System: KDE neon User Edition
KDE Plasma Version: 6.6.3
KDE Frameworks Version: 6.24.0
Qt Version: 6.10.2
Kernel Version: 6.17.0-19-generic (64-bit)
Graphics Platform: Wayland
Processors: 20 × 13th Gen Intel® Core™ i5-13600K
Memory: 32 GiB of RAM (31.1 GiB usable)
Graphics Processor: llvmpipe
Manufacturer: ASRock
Product Name: Z690M-ITX/ax

I was blaming it on Firefox. I have noticed that speeds are way off too. Never thought to look at the kernel. It has gotten downright painful. My updates this morning crawled along at 300kbps. It took ten minutes to download one update package. YouTube has become an exercise in frustration.

That being said, I notice your graphics processor is listed as LLVMPIPE. Typically you would see “Intel yadda ydda yadda” listed for an IGPU and AMD usually has its own opensource Radeon driver. I have only seen LLVMPIPE (Nouveau) with Nvidia graphics. Do you have an Nvidia GPU? If so, I strongly recommend installing the Proprietary Nvidia driver. This will dramatically increase your performance for many things; not just graphics but anything that uses CUDA or compute, which is a lot of apps these days.

If you need instructions on how to do this, just ask. I am happy to walk you through it.