I have very little experience with linux, so maybe this is a dumb question :)
I run Ubuntu 24.04 on a machine, and I had an old HDD in a usb-case which I mounted using fstab. Worked fine, but I decided it wasn’t appropriate for my purpose and removed it (physically and from fstab).
But it still shows up in the file manager? What am I missing?
I suspect that your /srv had already existed before you mounted that drive for the very first time, and there were even some files in /srv.
The mounting of the drive has made these “old” /srv files invisible. But it has not deleted them. Now you unmounted the drive, and they have come back like Zombies :)