Error making multiple insert

I have a form that generates multiple fields for adding data, and then sends all data using for , thus making multiple insert in MYSQL. However, I have a problem.

Let's say I generate 30 forms, of this total is only sending 20, and the others are not being entered into the database. I wonder if this is being caused because of the script execution timeout on the host, or it would be because the form is too large.

I left below the image of my form, along with the original code I edited.

Code for :

for($i=1; $i<=$total; $i++) {

Aqui fica o 'INSERT' da minha MYSQL

}

My form: click here

Original code click here