Hello. I don't know if this is the most appropriate forum to post this but, whenever I restore a minimized VirtualBox guest machine, the screen sometimes only shows a part of it. This happens when I turn full-screen on the guest OS and restore it after it was minimized.

https://i.imgur.com/ynBIh36.png

Doing it for the 2nd time seems to work fine, but then, when I minimize the window and restore it again, the same bug occurs.

I tested with the default VirtualBox that is in the Ubuntu repositores (5.2.18, I think), but it also happens with the latest version from Oracle's website (6.0.8). It occurs with Guest Additions installed and not installed.

Turning desktop composition on/off does not seem to fix this problem. Is there a way to prevent this from happening?

Using Xubuntu 18.04, 64-bits
Tested with Windows 7 and XP as guest OSes.