There are two things that seem particularly off in recent versions:
First the column headers on tables seem to have gotten a nearly unusably small divider between them that makes it very difficult to resize them; it seems that only the exact single pixel width of the divider can be grabbed and used to resize. Contrast that with Excel where 10 pixels before and after the divider between columns can be grabbed to resize. I don't think this was always like this, but maybe I only recently noticed. Either way, the "grab" area for the divider between columns definitely needs to be bigger.
Second, in Power Query editor I've noticed lately that there is a lot of flickering when moving the mouse around and this causes the window to act like I just interacted in some way. Example, I'll be editing in the formula bar, if I move my mouse around and it passes over other UI elements the formula bar will behave like I just hit the checkmark and try to process my formula even if I am not done entering it. Also if I right click anywhere and try to move my mouse through the context menu it will often act as though I hit escape / clicked out of the menu and close it before I can mouse over the menu item I want. It is now quite frustrating to try and work in Power Query editor at all because the interface is constantly bugging out, I can just mouse aruond over the power query window and it will flicker randomly. It wasn't doing this a few months ago.
Currently on Version: 2.109.1021.0 64-bit (September 2022)