My external drive is always magically used by some non existant app when I want to eject it

It’s grinding my nerves. 80% of the time I want to eject my external SSD, after closing everything that could be using files on it, I get this stupid message saying « an app » is using it. NO APP IS USING IT. Not even finder. I always try to force finder to close and it still doesn’t work. And how does finder prevent me from ejecting the drive anyway?? Does someone know the trick to fix this? Why is this problem not fixed but the 3 OS updates I get a notification for every hour? Thanks!