I recently did sudo apt upgrade and I think this upgraded my kernel to 5.13.0-27-generic. (I think I also ran sudo apt autoremove.) Since then my graphics have been worse, e.g. windows 'split' when dragging them across the screen, or when scrolling through text, and the cursor is slow to catch up if I have fractional scaling enabled.

I went to check settings in the Nvidia GUI which I'd used previously (I had it set to "High performance mode" or something like that before), but it doesn't come up in Activities. In Software & Updates it is still there with "Continue using a manually installed driver" selected, which I think is the same as before, though underneath it says "No proprietary drivers are in use".

If I run lsmod I don't see anything with Nvidia in the name, but I'm not sure that's relevant; I just read it on another post.

In Synaptic there are hundreds of entries for Nvidia, including ones described as "Linux kernel nvidia modules for version 5.13.0-27".

So where is the GUI and why have the graphics got worse?

Specs: Dell XPS 15 (9510), i7-11800, Nvidia GeForce RTX 3050-Ti