Excalidraw - display of pictures that were inserted with copy/paste not working anymore

When I insert a copy/paste image directly into a Excalidraw-note, at the beginning I can see the image properly. But after I have left the note and I return to it, it is not displayed correct anymore. Also in all my “old” Excalidraw-notes this happened.

I tried to insert an image with copy/paste in a new Excalidraw-note, it happens again and again.

I will open one of my backups on another computer in order do check, whether this is a bug that has to do with my laptop. But I think this won´t help me with my problem.