Thank you for your replies, and sorry for my late response.
The problem occurs at least with audio tracks I've recorded (and in my opinion, it affects all audio tracks).

It does indeed seem similar to the one reported by thomasc.

I've noticed that I don't have the problem when the selection is at the end of the track, as if the end of the selection itself isn't being registered.

Obviously, I've used the standard commands (shortcuts and menu items), and I've retested several times, including on a brand new project.