Since Oracle VirtualBox 7.0.2 (7.0.0 was never loaded) on the Tumbleweed
server, FreeBSD 13.2-RELEASE does not shutdown completely.  FreeBSD doesn't yet
have a 7.0.x version of Guest Additions and is "stuck" on 6.1.48 for now.

The problem is also observed on the upcoming FreeBSD 14.0-RELEASE.

The problem is also observed when the server is running Leap 15.5.
The problem is also observed when the server is running Fedora 38.

This problem was not observed with version 6.1.x on the Tumbleweed server.

The guest shutdown, whether "ACPI Shutdown" (from the Machine drop down menu),
"shutdown -p now" (from the guest console) or "poweroff" (from the guest
console), proceeds normally until the guest console displays "uhid0: detached"
followed by "uhub0: detached" and then just sits (forever).

You can use "Power Off" (from the Machine drop down menu) and restart the VM
with
everything behaving normally.

You can use "Reset" (from the Machine drop down menu) and everything also
behaves
normally.

The Guest VM doesn't appear to know anything about the hang.  All filesystems
have been flushed and unmounted properly. Subsequent boots of the system are
clean.  Nothing unusual is present in the system logs.

The VirtualBox logs do not have anything interesting in them (as far as I can
tell).