How do I figure out what's causing a bad redirect inside Moodle to my WordPress install?

I’ll try to make this brief. I have a WordPress/multisite install at my .com. I also have a Moodle LMS site at .com/course where I deliver courses. In one specific Moodle plugin that tracks student time, when installed it creates what looks to be a correct URL, but instead of the information from the plugin, the URL shows the sales page content from my main WordPress install. .com (Even though the link itself seems correct. .com/course/mod/attendanceregister/etc)

The plugin is working for other people and for the developer when he tried it on his own sub-directory. When asked for ideas the developer of the plugin suggested maybe I have some garbled Apache mod_alias directive?

I’ve tried turning off WordPress plugins, but I really don’t know how to track down the problem. Guess it could be Moodle/Moodle plugin, could be WordPress plugin, etc. I’m just looking for suggestions as I have to track time in course due to regulations and this Moodle plugin is my only option.