Sudden loss of audio output

Apologies if this is an issue that has been described previously, I’m not sure what to call it, so I’m challenged to search for it.

Twice in the last 2 days, seemingly unrelated to anything I am doing, Roon stops playing. It is usually between tracks. This time it was at the conclusion of a Tidal MQA 48/24 track and the beginning of a local low res mp3 file. At this point, Roon will move through the tracks in my queue, none of them actually playing. If I quit and re-start Roon, my audio output is no longer available. If I re-start my core, then everything is fine again. This has happened a handful of times since the update to 1.3, which for me on my very simple system has been otherwise rock solid.

Here’s my setup:

I’m running the latest build of Roon on a 2012 2.9GHz i5 iMac with 12GB ram. I’m up to date on macOS, 10.12.3. I’m playing via the optical output of the iMac to a Peachtree Deepblue2 bluetooth speaker that happens to have an optical input as well. My audio files are on an external USB drive. My library is about 41K, 18K local files, a mix of red book, hi-res, and some mp3/aac files with the rest added via Tidal.

While I don’t mind restarting my iMac every few days, sometimes I’m in the middle of work, (like right now!) and would prefer to listen to music and get work done over not being able to do either while my machine re-starts.

Suggestions are always appreciated, thanks!