Sorry if this suggestion is in the wrong forum.
The video in Cubase 10.5 WIN10 becomes choppy, frozen etc long before my computer audio bottlenecks. I fixed this by using a standalone application - MTCVideoSlave. However the 30day demo is finished and the guy doesn’t answer emails. Please move the cubase video engine to be opened separately outside cubase, linked to the program via MTC.
Thx