After I updated the system to
> FreeBSD xx.xx.xx 12.2-STABLE FreeBSD 12.2-STABLE #0 r365830M: Thu Sep 17 00:45:39 PDT 2020 firstname.lastname@example.org:/disk-huge/sys/usr/src/amd64.amd64/sys/GENERIC amd64
and packages 'kldload vboxdrv.ko' now causes kernel crash, making VirtualBox unusable.
The previous kernel was from 3-4 days ago and vboxdrv.ko didn't crash.
*** This bug has been marked as a duplicate of bug 249326 ***