I am fairly new to the square. I have notice that tips are not allowed on purchases for a low amount. For instance, we tried running a credit card for $6.00, the customer wanted to leave a $3.00 tip. The square app would not allow it. A second time occured where the credit card purchase was $4.00, the customer wanted to leave a $2.00 tip. The app wouldn't allow it. I read on the Square website that if a purchase is under $10.00, the tip can be only $1.00, $2.00, or $3.00. Can someone please help me fix this issue.