Sound stops working after leaving B3 & B4 open

I hav been finding that if I leave Beta 3 or 4 open for some time (a few hours) when I come back to it I get no audio to my speakers. The mixer registers sound but nothing goes to speakers or headphones. I have tried switching timelines and even projects but can onle resolve it by shutting the beta and re-opening

I also have this issue with the latest Beta 5. The first time I noticed it, I was working on edit for a few hours just fine. I exported my video and walked away from my computer. When I came back the audio wouldn't work when I went back to the edit page.

Audio was set to use system audio. I have my system setup to use my Focusrite 4i4. However, when I went back to check the preferences, it was showing the system audio was using my Jabra Pro 9470 Headset. The headset was not set as the system default, and I always manually set it for the audio and video apps that I use. Audio worked fine using my Focusrite on Windows system and other apps.

I then tried to set preferences to manual, and I manually selected my Focusrite 4i4. It worked fine for the next round of edits, but then I left for a while and got some lunch. When I came back, once again the audio wasn't working. After double checking the audio preferences, it was still set to manual but it still wouldn't work until I restarted Resolve.

I take it your Focusrite is connected by USB. One thing to check is that the USB hubs are not set to turn off to save power.