A vps update doesn’t require a reboot, so this seem like a program update.
By default updates are set to automatically.
If you have set it to manual it is still possible (and allowed) that avast forces a update.

You say that the new interface seems to be difficult to follow.
This is a very strong indication that you had a old version of avast installed and that a forced update took place.

I have no indication that something strange happened, it all seems perfectly normal.