that’s only half the story of course :
strictly speaking the CC121 isn’t fully supported on cubase 10.5 - apparently that’s coming. It’s supposed to be a fully supported product of course
CC-121 Erratic behavior with Cubase 10.5 - CC121 - Steinberg Forums and
https://helpcenter.steinberg.de/hc/en-us/articles/360010461459-Cubase-10-5-Steinberg-hardware-compatibility
midex 8 didn’t work with 64 bit OS for a long long long time - until SB relented and released beta drivers…too late for me as I’d long since disposed of mine.
MR816 isn’t supported under the current MAC OS