Comment 1 for bug 1890942

Versions on the "Ubuntu only" machine:

vagrant/focal-updates,focal-updates,now 2.2.6+dfsg-2ubuntu3 all [installed]
virtualbox/focal-updates,now 6.1.10-dfsg-1~ubuntu1.20.04.1 amd64 [installed]

Even after purging the users .vagrant.d directory to get rid of all plugins
and to force re-download of the ubuntu/focal64 base box it gets stuck on startup.

Also tried a box version from end of May, where things definitely still worked,
can't get that started anymore either now.