I was having a similar problem - If I had a You Tube video running and I switched back to Studio One, the video would either stop and just look like it was buffering, or the sound would drop out. I think I managed to fix it, as it isn't happening anymore. The problem was the sample rate for the computer speakers/Audio box were set differently - in the "sounds" setting on computer, the sample rate was set at 48khz, while the setting in Universal Control was set at 44.1 Khz.
Initially, I tried setting the Audio box to 48khz in UC, but it kept popping back to 44.1 khz (that is another issue with UC that I have a question into support about - when I click on the Audio Box Icon in UC, nothing happens - but I'm waiting to hear back). Anyway, I went into the "sounds" setting on my computer:
- clicked on speakers;
- clicked on properties;
- clicked on advanced;
- then changed sample rate to 24 bit, 44,1000 hz. I also made sure exclusive mode was unchecked. I read in another post that this may cause problems if it was checked.
SO I made sure these were the settings for the both sets of speakers in my sounds settings (Audiobox and computer). Not sure if I needed to to that, but since I did, everything appears to be working ok. I can switch back and forth between YouTUbe and Studio one, or anything else playing audio, and everything continues to play.
Hope this helps