That error doesn’t directly break Tor. It derivatives from the recommend/expected virtualizer configuration.
This is unrelated to UTC. It is about the pvclock setting. If you want more background on it, search the forum for kvmclock. See also Dev/KVM - Whonix. It allows an attack similar to the one described here TimeSync: Whonix ™ Time Synchronization Mechanism.
Did you change any settings in VirtualBox? The paravirtualization providers? Don’t.
This is unsupported, discouraged.
( [unsupported] VirtualBox now supports KVM and Hyper-V as paravirtualization providers )
Whonix 11 didn’t get any updates related to that recently. Did you update from the testers repository?