You probably need to inspect and possibly compare the permissions at the target location to other similar locations that work.
ls -l *directory *
If you don’t want to analyze and may not care what the differences might be,
Just delete(or mv/rename temporarily) the existing problem folder and create a new one, and verify the folder properties are identical to any other that works.
BTW - I’ve often found that there can be random issues in GUI file managers, likely because they seem to operate by overlaying their own file “view” over the actual file system. If the problem is related to the file manager, you can always perform the file operations using a command line. I don’t know if a command line ncurses file manager that supports a mouse might work, that’d be an interesting option.
That was it nrickert, the darned ::::::: is not permitted. Changing it to a ----- worked wonders.
I am forever in your debt and something to file away to be promptly forgotten the next time it happens. The format is fat32.