If you haven’t already, try hard-resetting your iPad (see steps below). Sometimes iPadOS gets in a weird state where nothing opens correctly and apps randomly crash.
Have solved this or I think I have, after testing many files in the Files app, found it’s a limitation of quick view in the app, max resolution it can display is 55mp anything over that quick view runs back to mama, flashes a white screen a few times and then displays a white screen with the file title, this does not happen in the Photos app.
Many of my image files are 70Mpix+ exporting as jpg or png from Vectornator.
If the max resolution is 32.000px x 32.000px means that the final file can be 1.024Mpx. 1.024Mpx is more than 70Mpx. Are you agree with me? Anyway if you can’t open this large files is a problem of Apple’s Files app.