Hello @MPDC thanks for your post. I would check each age restricted item, I don't know if you can set this "globally" for every sale, so you may need to edit each item. There should be an option to edit the item (drink, etc.) and mark it as age restricted. Here's the step by step:
Set an age restriction
Sign in to your Square Dashboard and click Items & orders > Items > Item Library.
Click Create item or select an existing item.
Click Set next to Age restriction.
By default, you will have three options for an age restriction:
Buyer must be 18+
Buyer must be 19+
Buyer must be 21+
Choose a minimum age restriction, then click Set.
You can also set up a custom age restriction. Click Custom and input your chosen age, then click Set.
Hopefully this will help with your issue. Maybe another seller more familiar with Square for Restaurants can offer better solutions instead of editing each item.
