I had this same problem with my M4. Audio in all other apps (including Cubase) worked fine, only Dorico had a problem. The only way I could find to resolve it (on Mac) was to use an aggregate device. See this thread:
I had this same problem with my M4. Audio in all other apps (including Cubase) worked fine, only Dorico had a problem. The only way I could find to resolve it (on Mac) was to use an aggregate device. See this thread: