PHP 7 shouldn’t be the issue as I am running Nginx with PHP-FPM 7.0.
What is the error you are seeing and where are you seeing it?
I am guessing the tech tried upping memory_limit, upload_max_filesize and post_max_size, is that right?
This looks like post_max_size or upload_max_filesize, which I am guessing are the “upload limits” the tech mentioned.
[13-Jan-2018 01:12:24 UTC] PHP Warning: POST Content-Length of 10490300 bytes exceeds the limit of 8388608 bytes in Unknown on line 0
Is the issue that you cannot connect to GPM in the Admin but you can connect to the ? GPM in the CLI? If so, are you running Grav 1.3.9 or 1.3.10? There was an issue in 1.3.9 that broke GPM’s connections which was fixed in 1.3.10.
If the install is running 1.3.9, update to 1.3.10. You can do so whole hog with the following links.
You should also be able to use the CLI with the following command.
Or are you unable to connect to the GPM via CLI and Admin?
Did the tech report what, if anything, was being logged to the web service’s error log? Since you have cPanel, you should be able to check the following for anything being logged.