So you use the Photos app? Photos is a non-destructive editor, so edits never change the original. But, of course, Photos editing is aimed toward photographs rather than drawings, so I get it.
Restarting in Safe Mode is does way more than just restart the computer.
In what app are the picture files created?
You haven't said how you try to duplicate the file. For instance,I would use ⌘D, is that what you do? I have no problem on my M3 MacBook with Tahoe 26.6.2 using command-D.
However, if I open a picture in Preview and choose Duplicate, I get a "Permissions" error.

On the other hand, if I use Preview to Export the picture, it works fine. I don't think that I have ever used Preveiw>Duplicate before…
If I use GraphicConvert>Duplicate, it works.
What is it that you do?
I looked it up: A "document" is "a computer file containing information input by a computer user." So Miriam-Webster thinks jpgs are documents.