Strange file permissions

I have a file (lets call it foo) on an external drive (formatted exfat) that has 1 file that I cannot delete. When I run 'ls -al foo' I get 'No such file or directory'. When I run 'ls -al' permissions for foo show as -????????? owner, group, size, and date show as ?

If I try to dele the file I get 'No such file or directory' if I try 'rm -f foo' it looks like it deletes, bus ls -al shows the file again.

Any ideas