It genuinely feels like it might be bugged for me. That, or I'm actually stupid and don't understand the coin denominations.
Ok, So let me run this scenario by you. A customer buys stuff for 17.75, they pay with a 20. I take the 20, put it in the register and give them three 1.00 coins and and one 0.25 coin. My math is correct and they should be happy, yet they still get mad. Is it possible that the bug carried over to the new version since I'm using an old save?