This is potentially a big problem. To get 3 RME Multifaces working together, for multiple I/O, aggregate devices doesn’t work on this platform - Cubase 11 on Big Sur.
This was OK on Catalina and CB 10.5 (and multiple other earlier versions).
My other DAW is coping OK with this aggregate device. Non-aggregate device (individual Multiface) works OK.
Luckily, I still have a Mojave volume - but whichever company needs to look at this, should take a look