FWIW, I changed my mouse and managed to fix this. I bought this one: https://www.amazon.com/gp/product/B00E290JRE
I looked for a mouse that could do a low DPI thinking that might be part of the problem. So if you are using a gaming mouse set to a high DPI (I had one set to 1000 before), try something like this set to 600dpi (it’s lowest setting). As far as I can tell, it seems to have fixed this intermittent but extremely annoying issue for me. I think “standard” mouse dpi is 800dpi.