I see this with flatpaks, the solution might be to grant permission to the app to the part of the filesystem your dragging from with flatseal/cmdline.
HOWEVER I do think the desktop is missing a pop-up which offers to do this for you when it happens. This is how android does it when an app needs access outside its own files, you just get a prompt to allow it.
This is the sandbox future - it's safer and you can trust that apps can't go snooping around your system but users shouldn't need to fiddle with perms all the time to get stuff done.
Once Upon a Time in America. Maybe I watched a bad version but it made little sense and the ending was dreadful.
Reading about it right now on wikipedia I probably saw the 'condensed' version which was savaged by the critics:
https://en.wikipedia.org/wiki/Once_Upon_a_Time_in_America