This problem ist back for me on windows 10 right now.
Application paint.net v4.3.2 (Stable 4.302.7947.34042)
Build Date Montag, 4. Oktober 2021
windows 10 ltsc 10.0.17763 build 17763
A fix would be most welcome. Working with a larger amount of pictures becomes impossible if you only see paint.net icons and not the preview thumbnail.
Thanks!