I've had this happen on one person's computer that I tried doing some bug hunting on and also couldn't find the issue unfortunately. It might be an issue with Godot itself, in which case I'll need to go to the forums and see if anyone's else has this issue.
Hello hello!!! Excellent game, I had this issue as well but figured out what was causing it, the game doesn't seem to have any v-sync enabled, causing it to overproduce frames and go at super-speed. Going into any GPU control panel and manually setting the program to use v-sync seems to fix the issue!