Bug confirmed for me with VirtualBox Version 6.0.4 r128413 on 4.4.0-143-generic, reverting back to 4.4.0-142-generic resolved issue also.
Bug confirmed for me with VirtualBox Version 6.0.4 r128413 on 4.4.0-143-generic, reverting back to 4.4.0-142-generic resolved issue also.