So I am using the Mate desktop with the normal Caja file manager. When I go to upload a file somewere, the interface is just a mess. Is there a fix for this?
That's GTK4's problem and nothing to do with the file manager. It's just using the GTK4 file picker, and I haven't found a way to either make it accessible or force it to use the GTK3 one. Hopefully with this redesigned file chooser that's coming that adds thumnails, we'll have something a bit more aaccessible.
It's popping up in any distro like Fedora or arch that's reasonably up to date. This new GTK4 file chooser to open, select, or do anything with files that isn't the file manager itself is proving to be really annoying to orca users.
For apps like firefox that override this and use the GTK3 file picker, they'll carry on as usual. But the second an app wants to use the standard one though, that's GTK4 and there's no getting around that unless there's a variable I'm missing.