Normally when lister displays a root directory of given disk Go UP moves to Computer. This does not happen when the disk is not present. Then Go UP does not cause any visible effect.
This problem exists from long time, but I'm not sure whether it was reported earlier.
Directory Opus Pro 10.5.4.0 (5080) x64
OS 6.2 (B:9200 P:2 T:1) SP 0.0
It seems to work OK here, trying with a USB stick that I navigated to and then unplugged. Going up a level worked OK.
What kind of drive are you doing it with?
Removable (USB pendrive) and fixed disk (temporarily disconnected).
And seems like it does not matter whether a lister displays a root directory from previous session, or a root of newly inserted and removed drive.
P.S.
It is not big problem for me. I just reported it, but if it is something not affecting other users and difficult to reproduce for you, it may be something not worth an investigation.