FIX PHP WEBSITE ERROR

Hello there,

I need a professional who knows php to fix my website error.

I have a website for booking transfers online, so when a visitor stays for more than couple of minutes in the Booking page then after he proceed and waiting the confirmation it was coming that page (image 1) and not the correct page (image 2).
Then my developer make a small change so when the code hit or the page timeout, the website take the visitor back to the homepage.

I need someone to fix it and so no matter how long time stays a visitor at the booking page, when he fill the form and click to proceed, the booking to be confirmed normaly.l

Waiting for your offers.