Stuttering HDMI audio, Macbook Air M1 2020, MacOS 12.5
I had a Macbook Air M1 (MacOS 12.5) that had stuttering HDMI audio but the HDMI picture/video was fine. Originally I used a 3rd party USB-C to HDMI adapter but the problem also persisted with a brand new $69.00 Apple Digital AV Multiport adapter.
The user had numerous apps open (10+). They also had not restarted/shut down their Macbook in 40 days! After shutting down and restarting the computer, the HDMI audio worked again.
Solution: Restart the Macbook and try again.
MacBook Air Apple Silicon