PHP scripts running on one Cpanel but won't run when copied to another

I am not a developer but I am duplicating some integrations from one client's Cpanel (let's call this Server 1) to another and the scripts don't seem to run on the 2nd client's server (Server 2). There is a script that runs on a page built in Clickfunnels which sends submission form data to 3 different PHP files on the server, which then add new contact data to Everwebinar and Infusionsoft. Everwebinar seems to be receiving the data just fine, but nothing happens with Infusionsoft. There is supposed to be a redirect after submission but the page just reloads instead. If I point the script on the page to Server 1 then it goes through with the redirect. This leads me to believe the issue lies with the 2 files that initiate the contact creation and redirect through Infusionsoft on Server 2. I've torn apart this integration and rebuilt it several times. I've also checked the file and directory permissions and compared them against the other Cpanel settings but everything is the same. Can anyone please point me in the right direction of any other settings I should check?