Audio glitching when using Ultrastudio 4K as mac sound card

I have an Ultrastudio 4K connected to an iMac. When using the computer to playback audio (ProPresenter6), the audio plays back great. If you let the computer sit for a while and then try to play a video file with audio again, the audio sputters and glitches. When you select the built in speakers and then the Ultrastudio again, the issue clears up.

How can I fix this?

any luck in troubleshooting this. i have a completely different setup and use case but similarly have audio sputtering when using a decklink studio 4k but playback is fine from internal speakers

I've had the same problem for years. With the post production company we set up we bought a number of Blackmagic express and extreme cards that all had that issue.

I now have a studio at home with a Black magic 4K mini and, again having that same issue. It's more noticeable when the CPUs seem to be running, not highly but in a specific way.

When I do spotlight searches, for example, the twitching and glitching in the audio it's very noticeable.

Obviously this is a Mac/Blackmagic compatibility issue and is not limited to specific firmware packs.