Unstable work of Corel Painter 2021

Hey, guys!
I bought Corel Painter 2021 and i fighting with it more than 5 weeks. The problem is looks like unstable work of software. For example, you can drawing 4 hours and than, opportunity of changing tools is starting work unstable. You can't change tools and make remove of steps. 
I already talk with Support Team of Corel, but, all their advices doesn't work, or allow to work 3-4 hours and then you must delite temp files, reset settings to factory settings and restarting PC again and again and again.
Maybe someone has faced the same problem?
Please, help me with it, because i like drawing in Corel Painter and i want to work in it without problems. I just want to opening it like Photoshop or Clip Studio and having fun.

You can check out this video, where you can see how this problem looks.