在winforms / C＃中使用graphics.drawline时滞后

Beginner coder here getting into C#.. I'm making a program that involves drawing. Basically whenever I'm moving my mouse to draw, the actual line on the image appears delayed - and it's more.. straight, than it's supposed to be. It used to work fine, but at some point I guess something went wrong - can't remember what I did at the time so it's hard to retrace.. I tried to replicate just the drawing part of the program in a new solution, and it seems to work fine.. Beginner coder here getting into C#.. I'm makin