Several visual issues and lagging on MX250

[Štefan Földesi]

After the latest kernel update (5.4.0-45-generic) with the newest version of this package, several visual issues occured:

 - Cairo-Dock is grainy and semi-transparent (not caused by compositor)
 - Text in several applications is grainy and blurred (i. e. in Vivaldi and others)
 - The GTK theme visual effects are laggy (Material Design -like Ripple on button click)
 - Dolphin Emulator visual and input lag in some games

Uninstalling Nvidia drivers and using Nouveau fixes it (althoug Nvidia drivers performed better overall).

Using Ubuntu 20.04 LTS
nvidia-graphic-drivers 450.66-0ubuntu0.20.04.1

I ran apt full-upgrade, which upgraded my linux-image package to linux-image-5.4.0-45-generic. After reboot, I expected it to work just as it worked before. But the above described issues arised. I had to remove nvidia drivers and use nouveau, but now my performance is degraded.

[Štefan Földesi (geeshta)]

I also tried reinstalling the drivers so the modules were rebuilt, but the issues occurred again.

[Štefan Földesi (geeshta)]

Some additional info:

I'm using Xubuntu 20.04 LTS, XFCE 14.4, GTK versions:
libgtk-3-0:amd64 3.24.20-0ubuntu1 amd64
libgtk2.0-0:amd64 2.24.32-4ubuntu4 amd64

I don't know whether output of any tools could help, given the issues are mostly visual glitches and lag.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.