Thanks for sending through the profiler log. I’ve checked it out and in all cases the stalls were caused by plugins. Here you can see, Cantabile is running smoothly but the actual call to the plugin (ie: the plugin doing it’s processing) stalled:
The one case where Cantabile itself stalled was here but that was because it was waiting for the other (stalled) instance of (Xpand2) to complete. What do you have Options -> Audio Engine -> Multi-Processor Mode set to? (aggressive or compatible). Switching to aggressive might help that second instance, but not the original stalled instance.
This happened with two different plugins (xpand2 and SynthMasterPlayer), so my guess is this morely is a system configuration thing than a problem with either of these plugins and unfortunately probably your best bet to diagnose this is going to be trial and error. I’d try disabling things like wifi, bluetooth, onboard sound card and see if any of these make a difference. Also, as an experiment try a different audio driver.
Also you suggested this started when switching to Performer… just to double check I’d be interested to hear if this still happens if you switch back to Solo. (I’ve issued you a license for Solo so you can try).