Hello! Every time I've tried to use the new version of Krita (4.0 and above) I've been running into the same issue. I thought it might be my computer that was out of date, and after updating it, nothing changed. The best mode of explanation is visual, so...
With a larger canvas size: https://www.youtube.com/watch?v=btzN13fUljs
With a small canvas size: https://www.youtube.com/watch?v=j4P_3Xg230g
Image of With OpenGL vs Without OpenGL: https://www.deviantart.com/elizacatt/ar ... 1547494028

Please help me! I've been using Krita 3.2.1 (because it doesn't have this problem) but I really want to join the Krita 4 party!

Well... You also asked this on irc... Please tell us _exactly_ what hardware you have. Which OS, and which version of the OS. What tablet, and which tablet driver. It looks a bit like a broken Huion driver, but that's just a guess, of course.