files can reappear if you had them backed up to a cloud (ex. Google One) and is continually re-syncing and updating the phone based on the files saved in the backup.
so... check your backup setting
not sure what else could be causing this 'reappearing' of files...
you could reproduce the issue and report to samsung members app > get help > error report.
something helpful is to take screenshots of the before/after to help the samsung engineers understand better what is happening