Made symlink F:\Downloads which points to G:\Downloads
Put a file in F:\Downloads
Used Move As command to move & rename the file to G:\
The file was moved & renamed, and the original file was no longer there.
Is the original file really still there, even after a refresh? (Junctions can complicate change notification, so it's possible it isn't there but just looks like it is, perhaps. That should not happen either, but if it is what's happening, it changes what we need to look at.)
Is it still there after a reboot? (If not, something was locking the file, shared for deletion, and the file was only fully deleted after whatever it was exited.)