Comment # 11 on bug 1178360 from Stefan Hundhammer

After upgrading the last remaining package
virtualbox-kmp-default-6.1.14_k5.9.1_1-2.6.x86_64 it STILL works.

But I noticed that zypper also downloaded a new kernel package while I was
upgrading (see comment #10) despite having cached everything before ("sudo
zypper dup --download-only"). I now have kernel-default-5.9.1-1.2.x86_64 in
that VM.

So maybe it was that latest kernel that fixed it. I have no other explanation
to offer. !?!?