Hello!
Yes, this is an issue tied to the refresh rate, as you've noticed. I intended this as a fix as internally, the default idling process of the program eats up the remainder of the main CPU core as a means to maintain a consistent framerate. As this was not acceptable, I decided to rely on VSync to time the application. This seemed like an acceptable alternative at the time because I only had a 60 - 75hz monitor. However, I completely neglected to think of people who have monitors with higher refresh-rates where the program would simply run faster on their computers, haha.
I'll see about fixing the timing using my own methods and pushing out a build tonight; apologies for that!