Just giggled as my last meme mentioned trouble with displays and appropriately, a large chunk of the replies were “well MY displays work just fine!” (And charmingly, many were thoughts of things to check, other distros etc. It’s a very kind community, though that may also be the fediverse.)
Yep, know about that. Set it up back when I tried a few Debian-based distros with Gnome. I’m using Plasma with Dolphin as my file manager now, which has its own thumbnailer that relies on icoutils. I’ve got the whole thing set up and enabled, it just… doesn’t work.