The freezing is not an Ubuntu problem it's a GNOME problem.
Ah, on re-read of the OP comment, it's "wifi issues and freezing", two different problems they had. Have never seen either from GNOME though.
GNOME is very slow. The UI and animations are implemented in JavaScript. KDE Plasma isn't much better though. You should try using a tiling window manager.
This should be a criminal offence
Can you point me to the code implementing an animation in JavaScript?
https://gitlab.gnome.org/GNOME/gnome-shell/-/blob/0db41a3773...
It's everywhere
Or just a sane floating one like Fluxbox. Taskbar, systray, window merging by title, Zukitre themes to match the GTK ones and dead simple to setup, with no XML such as the "other one".