I received the same guidance from Apple support over the phone. However, this only works for a short period of time. The issue will resurface within the same day or next day. Sound output is cutting off in the middle of video/tele conferences while working from home. This is a major show stopper and I have had to resort to calling into conferences from my phone to avoid cut-off.
Observations: Apple Music will glitch the audio every couple of minutes but the speakers will recover and start playing music again with no intervention. However, during Zoom/WebEx/Google Meet meetings, the speaker audio will cut-out and won't return. I have to hang-up and call back. Big productivity killer.
Apple, please address this bug.
My setup: 2019 Macbook Air, Catalina 10.15.4, Apple USB-C to HDMI dongle connected to HDMI monitor (no speakers). Attempting to use Macbook built-in speakers for all audio.