Shutdown errors and timeout

Hello all, i have two FreeBSD 13 machines, one is a bare metal and one 
is virtualbox machine which i both update about once a week.

The vritual machine seems to fail stopping something and gives a timeout 
after 90 sec.

The console ends with

Writing entropy file: .
Writing early boot entropy file: .

90 second watchdog timeout expired. Shutdown terminated.
Fri Nov13 11:20:40 CEST 2020
Nov 13 11:20:40 test-head init[1]: /etc/rc.shutdown terminated 
abnormally, going to single user mode
...

On the bare metal machine i see the following.
Writing entropy file: .
Writing early boot entropy file: .
cannot unmount '/var/run': umount failed
cannot unmount '/var/log': umount failed
cannot unmount '/var': umount failed
cannot unmount '/usr/home': umount failed
cannot unmount '/usr': umount failed
cannot unmount '/': umount failed

The virtual machine has the following mount points set.
zroot/ROOT/default on / (zfs, local, noatime, nfsv4acls)
devfs on /dev (devfs)
fdescfs on /dev/fd (fdescfs)
zroot/var/log on /var/log (zfs, local, noatime, noexec, nosuid, nfsv4acls)
zroot/usr/home on /usr/home (zfs, local, noatime, nfsv4acls)
zroot/jails on /jails (zfs, local, noatime, nfsv4acls)
zroot/tmp on /tmp (zfs, local, noatime, nosuid, nfsv4acls)
zroot/var/audit on /var/audit (zfs, local, noatime, noexec, nosuid, 
nfsv4acls)
zroot on /zroot (zfs, local, noatime, nfsv4acls)
zroot/var/crash on /var/crash (zfs, local, noatime, noexec, nosuid, 
nfsv4acls)
zroot/var/tmp on /var/tmp (zfs, local, noatime, nosuid, nfsv4acls)
zroot/usr/ports on /usr/ports (zfs, local, noatime, nosuid, nfsv4acls)
zroot/var/mail on /var/mail (zfs, local, nfsv4acls)

The barematal one
zroot/ROOT/default on / (zfs, local, noatime, nfsv4acls)
devfs on /dev (devfs)
fdescfs on /dev/fd (fdescfs)
zroot/usr on /usr (zfs, local, noatime, nfsv4acls)
zroot/var on /var (zfs, local, noatime, nfsv4acls)
zroot/tmp on /tmp (zfs, local, noatime, nosuid, nfsv4acls)
zroot/usr/home on /usr/home (zfs, local, noatime, nfsv4acls)
zroot/var/log on /var/log (zfs, local, noatime, noexec, nosuid, nfsv4acls)
zroot/var/run on /var/run (zfs, local, noatime, noexec, nosuid, nfsv4acls)
zroot/var/mail on /var/mail (zfs, local, noatime, noexec, nosuid, nfsv4acls)
zroot/var/crash on /var/crash (zfs, local, noatime, noexec, nosuid, 
nfsv4acls)
zroot/var/db on /var/db (zfs, local, noatime, noexec, nosuid, nfsv4acls)
zroot/var/empty on /var/empty (zfs, local, noatime, noexec, nosuid, 
read-only, nfsv4acls)
zroot/usr/src on /usr/src (zfs, NFS exported, local, noatime, noexec, 
nosuid, nfsv4acls)
zroot/usr/ports on /usr/ports (zfs, local, noatime, nosuid, nfsv4acls)
zroot/usr/obj on /usr/obj (zfs, NFS exported, local, noatime, nfsv4acls)
zroot/var/tmp on /var/tmp (zfs, local, noatime, nosuid, nfsv4acls)
zroot/usr/ports/distfiles on /usr/ports/distfiles (zfs, local, noatime, 
noexec, nosuid, nfsv4acls)
zroot/usr/ports/packages on /usr/ports/packages (zfs, local, noatime, 
noexec, nosuid, nfsv4acls)
zroot/var/db/pkg on /var/db/pkg (zfs, local, noatime, nosuid, nfsv4acls)

The pools have not been upgraded after the latest openzfs import, maybe 
that is related?

FreeBSD test-freebsd-head 13.0-CURRENT FreeBSD 13.0-CURRENT #2 r367585:

First thing i noticed is about a week ago.