Issues like that can be frustrating, I just went through some PC issues myself, but totally unrelated to Cantabile. FWIW I, and many others on this site, have been gigging with Cantabile for many years.
I personally never had an issue with it at all.
I did have one issue with the PC itself once, but a quick reboot was able to get me through the gig (The offender was an AVG update even though I had previously set AVG to be disabled.). That said, most of us have a backup rig. Just like how I carried a backup amp back in the day.
As suggested, info and even screenshots of all your settings in Tools may be helpful. Sounds like you have something else significant going on, maybe with your PC, interface or driver etc. You’ll find that there are a lot of very talented and experienced folk on here who will help you. Including Brad, the developer.
Tom