cubase 10.5.12 missing audio interface on start up

My Mac shows my audio interface Steinberg UR824 as working. Load Cubase 10.5.12 ok, but on loading a project, i get a missing ‘not mapped’ error message. Why can’t Cubase find the audio interface? I can play Quicktime audio through the interface, but Cubase isn’t connecting. Any ideas why? This entire set up worked 24 hours ago with no issues. 10.5.12 is recent and now this.

oh I might add, Cubase 10.0 loads and works fine.

Logic Pro X runs fine too.

solved. for whatever reason, cubase 10.5.12 wanted the built in audio on the Mac as default audio. Simply selected UR824 to fix it. thank you google.