I’m on:
PHP 7.1
(Apache)
SuiteCRM 7.11.2
Mautic 2.15
But I’ve had this working on many previous versions of SuiteCRM and Mautic for over a year at least.
Hmm, I don’t see anything wrong with your setup, Have you tried re-setting your file permissions in SuiteCRM? This is always the first thing I do when there’s no obvious problem, and it fixes so many issues.