Oh goodness.!
I see my sneaky, ‘naughty little friend’ (that I ‘discovered’ for the first time back in February) continues to catch people out… 
Cubase Pro 14 - CONTROL ROOM went silent - Cubase - Steinberg Forums
I can only join in as others have said though - the Control Room in Cubase is a great part of the app, something I’d struggle to do without. Other DAWs have only recently begun catching up with adding the kind of workflow flexibility it helps provide… Yet sure, I know, for some it is also not a ‘must have’…