Cubase lost output

I just started Cubase and there is no sound output. It has been working fine for weeks. All other audio outside of Cubase works fine. In the Audio setup, the input buses from my audio interface are present and correct, but the outputs, and only the outputs, are not present. When looking at the output bus the bus has reset itself to my (never used) video monitor audio as its output bus, and the audio interface does not even show in the dropdown menu for selecting the output bus. I’ve restarted Cubase, rebooted the system and every variation of the two. My audio interface is present and correct and works perfectly with the windows sounds and shows and works as normal in all other sound capable software. The only problem is Cubase and ONLY the output bus. Cubase seems to have got itself stuck, so is there any way I can force it to re-check for the audio interface?
PS I have the latest update of Cubase 9.5 Pro and a focusrite 18i20 2nd gen and at about midnight last night when I shut down they were working fine. I switch on this morning and…nothing.

Is Focusrite ASIO selected as your audio driver?

Yes, it is (was). But I reinstalled my focusrite control software (still no joy) then went back the audio settings in Cubase and the output device was then visible in the drop down menu. It STILL didn’t work, so I DE-selected the driver, rebooted everything, Reselected the correct driver and Bingo. Success.
Something got confused somehow, but all my messing around seemed to have sorted it eventually. Thanks for the advice though, it was actually correct, as I think, even though the correct driver was showing in the window, it wasn’t Actually selected. (It was one of the first things I checked originally, but I forgot to mention that in my original rant.

The 9.5.30 update decided to deselect my outputs in the control room and use the regular outputs instead.
Also direct monitoring was not working correctly, until I selected a different ASIO driver and back to the original driver.