Glitch or bypassing phone field restrictions

I’ve recently had a submission where the data collected on the phone field, seemed to bypass the restrictions and not sure how.

I have a phone field that limits inputs to the US. When I did my testing the field worked properly and it does not allow me to type a ‘1’ as the first number (the field does not even admit the character to begin with), and also it does not take any more inputs after the 10 digits are written.

However, I received a submission with 11 digits, because the user apparently typed the 1 code. But I don’t know how he did it.

Here is the submission:

And if I go to the form submission to see it on the actual form this is the input that appears where you can see 11 digits (blurred some for privacy concerns):

I cannot reproduce the error because the field seems to be working correctly if I try a blank form submission. Also, this happened only with this submission so it is not a recurrent issue or bug.

Could this have been a glitch? It was not a huge issue but it did mess up the mapping with my CRM, so reporting just for QA.

Thanks

Thanks for flagging!