Problem with text field validation

Hi! The plugin has been super useful to me but I’m having a problem with text input fields not validating (if required) and not reporting (if optional).

My custom products are kind of like sports jerseys in that the customer can choose a number to have me print on the product.

If user enters “00”, or any text that would evaluate to zero, it does not pass form validation and does not save the info and report back to me in my final order. Leading zeroes work fine (01, 001…), but all zero does not.

Any advice for where to go in and fix this myself? I can hunt for it in the code but I’d appreciate it if someone who knows where this piece is located could tell me!