camera issue

hello all.
im having a issue with freecam where whenever im going straight either in the map editor or just trying to move a car the mouse will all of a sudden start flickering and the camera just randomly starts going in different directions for no real reason. i tried unplugging my mouse and checking all my settings even checks in game to see if theres something wrong but nothing has worked.
if anyone can help please reply. thank you

 

Can you record it please? It's alot easier to understand than text.