I have created SD card with Ubuntu Desktop 21.10 using Pi Imager. It boots fine but when I interact with desktop environment, e.g. re-arrange the icons, the desktop environment freezes. When it's frozen, I can still ssh into it from another device on the same network and use anything that does not require graphical environment (e.g. I can use htop to see that the system is actually running as usual and the issue is with GUI).
Initially, I used the default DE this Ubuntu image comes with (Gnome shell) and when it got frozen, I was able to ssh into Pi and kill gnome-shell process which got me back to log in screen. I was also able to change some display-related settings (resolution, scaling, etc.) without it freezing but eventually some interaction with the environment is always making it unresponsive.
I figured that maybe a different desktop environment would solve the issue so I installed MATE desktop through tasksel. After re-boot, I started using MATE, but it was even worse: I wasn't even able to change screen resolution, because when I clicked on the menu and then "Preferences", it froze. In this case I was not able to locate the process which I could kill to restore the environment without a reboot.
In both cases, I can use GUI apps (such as Chromium or kdenlive video editor) as long as I launch them from terminal (in the case of MATE, I was able to right-click on the desktop and select "open in terminal", in the case of the default Gnome shell, I was even able to launch terminal from the usual menu and "Add to favourites").
It's challenging to determine what exactly triggers the freeze because when I use GUI applications launched via terminal, I will eventually click something that freezes everything.
How can I troubleshoot what part of the desktop environment causes the issue (so I can eventually fix it)? Also, since with the default image it's gnome-shell that seems to be freezing, what are some good alternatives proven to work on Pi 4 (I am used to Unity on Ubuntu and also Gnome, but I can switch to anything to have Ubuntu working)?
Raspbian 32-bit and its LXDE environment work just fine (so the issue is Ubuntu-specific and not related to power supply or SD card reader) but I need 64-bit system, preferably Ubuntu, for better performance and some software which only runs on 64-bit systems (e.g. Sublime Text 4).
