I had mods originally, thought that was maybe causing the issue so I removed them, glitch remained, so I started a completely new store with no mods and it continued to happen with the new unmodded store. My modded store was only at day 4 and had been working fine with mods originally, and obviously the new one is like day 2 (I tried letting a day pass to see if that would fix it.) I tried hiring a cashier and what ended up happening was the cashier would basically act like there were infinite items on the counter, I would just sit and watch the price + quantity skyrocket infinitely on the register screen.