every time there is a update of univention-base-files it will break the network connection of VMs and some services (DHCP at least) until reboot of the host. It would be very nice if this could be fixed, e.g. by splitting the package into two.
It’s annoying that such a little packages forces a reboot.
as this is clearly a bug, please file a bug report. Chances are much higher it’ll get looked at if there’s a bug report for it instead of lonely forum posts. A quick search didn’t reveal any existing bug reports.