PHP, jQuery, AJAX: Can insert one type of data to database

I have simple jQuery AJAX which from HTML form through PHP gets some data and makes it in the background.

Also, I’m using phone numbers this library.

Both scripts work fine but when all data are inserted into the database the phone number is not inserted.

When I try to use the form without Javascript, only with PHP script all data also with phone number is inserted.

In my opinion, the problem will be in AJAX and I can’t find it.

Is there any solution how I can fix it?

My code is on this link