I had the exact same problem on one of my virtual boxes. The problem baffled me for two years and I just added more space to the box a few times to fight it as I couldn’t solve the issue. It wasn’t the inodes, deleted but open files or anything common like that.

The problem was my mounts. I had occasionally failing mounts combined with crontabs that accessed and wrote data to those mounts. Do you know what happens when you accidentally wrote let’s say 200gb data to /mnt/a and then later mount a drive over that mount point? It magically ‘disappears’ as you’d exclude that mount from the calculations.

Might be you don’t have anything mounted and none of the above is useful to you. But this solved my issue and it’s quite curious and silly. Just set up mount points to not be writeable and problem went away.

I used Linux Mint and GTX 2070 for over a half a year without any major problems. Installation was incredibly easy as there was a dialog box asking to install drivers and everything just worked. I have 4 monitor setup even.

Ultimately I switched to AMD (last week) because of the tiny problems that I experienced but mostly because I wanted to support AMD and could reason for an GPU upgrade.