Dragging icons in the desktop or dolphin is quite laggy during an X11 session

Hi there. Over a week ago I bought a new laptop, namely a 2022 Lenovo Ideapad 3i. It didn’t come preinstalled with anything so I decided to load it up with the latest version of Kubuntu. My experience has been mostly positive until now, but there is one major source of annoyance. While I’m on an X11 session, when I drag any file or program icon, be it in the desktop or the file manager, the icon always lags behind cursor; it freezes in its place until the cursor stops moving, then moves there. This problem does not exist when I’m on a Wayland session, but the problem with Waylnad is that it does not support proper fractional scaling, unlike X11. Is there solution for the aforementioned issue? Any help would be appreciated.

My laptop specs:

Laptop model: IdeaPad 3 15IAU7
CPU: Intel Core i7-1255U
RAM: 8GB DDR4 @3200 Mhz
OS: Kubuntu 23.04
KDE Plasma: 5.27.4

Just to hijack your post a bit, can you comment on “the problem with Waylnad is that it does not support proper fractional scaling, unlike X11”. What exactly do you mean, and which parts of the system are affected?

If I go the display configuration settings under the Display and Monitor tab, and then set the display scale to something like 125%, if I’m using Wayland the screen will look all blurry, as if all it did was zoom in without doing any real upscaling, this does not happen when I’m using X11.

Did you reboot after changing the scale?

No, but I’ll try that when I have the chance.

If you didn’t reboot, that was the problem. With Qt5, you need to quit and restart apps before the new scale factor takes effect properly in Qt5 apps. In practical terms, you need to reboot. In Qt6, this is fixed.

Huh, would you look at that, this actually fixed the problem! Thank you very much!


And yeah, I know it should probably show a message when you change the scale that tells you to reboot. It actually does on X11, but on Wayland since scaling is per, screen it’s more technically tricky to do and I failed the last time I looked into it. And because the need to reboot afterwards is fixed in Qt6 anyway, I lost motivation and gave up.