I have two audio interfaces, both set at 48K. With studio one v5, I can select each individual interface with no issue. I created an aggregate interface in coreAudio, but whenever I select that, it causes studio one to slow down to a crawl.
If I quit and restart studio one, it tries to use the same aggregate device on startup and keeps flashing a "Restart requested by audio device" multiple times and then it's back to being really sluggish and slow. Another observation, is that if I do a clean re-install of studio one v5 (and remove all the settings folders), it will start up and force my aggregate audio device to 44.1K and work normally. However, as soon as I open a song or create a song in 48K, it goes back to the initial problem. And then I am stuck at 48K.. even if I change my interface back to 44.1, studio one forces it back to 48K and slows down.
I have studio one v4 installed on the same machine and it has absolutely no problems with the aggregate device. Also have Logic & Ableton both of which have no problems.
I am on Mac OS Big Sur