Installed by Xubuntu on 18.04. When watching a video, sometimes a diagonal line appears, while scrolling a web page the same way. When you move the window on the desktop, lags are visible. I made 2 videos, it can be seen there:
For the test, installed Mint 19.2 (based on Ubuntu 18.04), same problems. Mint 19.1 used to be - everything was fine.