It is not helped by the use of two tables and a mixture of content controls and form fields. Frankly it would be better if you used form fields throughout - see attached. The code will fire when you click out of the last content control.
Normally I would recommend locking the controls, as some fool will accidentally delete them, so I have only locked the controls in the table. The newly added ones are not locked while testing, but you can easily fix that in the code by releasing the three lines of code that lock them.
You may find
Insert Content Control Add-In useful.