Display scaling is causing lags and other issues

After a recent update, I noticed that my vlc player buttons and other icons had become huge. When i inquired about it someone said it was probably a scaling issue. I changed my scaling to 140% from 150, and restarted vlc, and the buttons went back to normal relative size. So I changed it back to 150 and restarted vlc, and it looked fine again.

After that though I started getting a lot of lag on my mouse (trackpad on a laptop), and since the only change I had made was changing scaling, I changed it to 140, then 150 and restarted my system. the mouse has now gone back to normal, but the vlc buttons are again huge.
Any idea why this could be happening?