Good evening, the lag are very evident and even if imposed the effects of plasma with xrender are still visible. If I remove the dock everything goes back to normal. I am attaching the debug file.
In fact, on ubuntu 18.04 I had no problem with any lag.
It doesn't allow me to attach the file. I enclose it with connection via gdrive
https://drive.google.com/open?id=1wa...h_w2132Fj25snP