(In reply to Larry Finger from comment #5) > Some critical information is missing: > 1. What is the host OS and VB version? I gave both information above: openSUSE Tumbleweed 20180627, VirtualBox 5.2.12_SUSE r122571. Please note that only the GUI is affected, not the window(s) with the guest OS. So ... > 2. What desktop is the guest running? ... I'm not running any guest. The program "VirtualBox" has the bug.