After reading your profile, I thought you might be a good match for this project:
I’ve got a “sticky”, issue with a 3rd party component (AcyMailing - [url removed, login to view]) on a Joomla! 3 client site that I believe is (at least partially) due to the host PHP version (5.6.3 — deprecated at the end of 2018) which, if I change to a more recent version, breaks other, required, custom PHP code (an API integration with a hosted scheduling service and RSForm! Pro form). I need that code updated to run under the latest PHP version and, while we’re at it, identify and fix a Joomla login sessions issue wherein the user’s token/key is apparently lost after editing/saving content (front end and back end) forcing admins to clear browser cache and reload the page in order to regain access during a session.
This is one of a few other issues on this site, and others, that will need attention going forward. I am a semi-retired, self taught Web/graphic designer comfortable with Joomla! CMS , HTML, and CSS; novice with PHP and MySQL. The custom code I mentioned was done by another freelancer recently and will likely need some clean up… s’not pretty!
I can provide access to a staged version of the site and/or snippets of the custom code if you require further info to accept… pretty quick turnaround is needed. (NDA is required.)