External drive won't properly eject smoothly
"Failed to unmount external disk because it's still in use."
How do I see what is still in use? I can't eject it, Disk Utility won't eject it. I have manually closed everything (no dots under programs), restarted finder, emptied trash, no joy. After exhausting those options I clicked
"Force Eject" where it did eject, but when I plugged it back in and ran disk utility's first aid, it failed to run again. Thanks in advance, Steve.
[Re-titled by Moderator]
MacBook Air (M2, 2023)