RH certified collection 'microsoft.ad' missing modules when used with execution environment

I'm having very limited success with building custom execution environments that have the collections I need. In this case, the collection I need is the 'microsoft.ad' collection (available on either RH Automation Hub or galaxy.ansible.com).

I have the collection and it's dependencies listed in requirements.yml/txt (I've also added these within the execution-environment.yml for v3). The execution environment appears to build as expected, and when I run 'ansible-navigator collections' the collection appears to be installed. However, further inspection of the collection reveals that it's missing some of the modules/plugins. Depending on which version of the collection I install, different modules are missing. If I install the collection externally from the environment in a subdirectory of my working directory (./collections), the same thing happens; ansible-navigator sees the collection as installed but a bunch of things are missing. If I install the collection externally in (~/.ansible) it gets installed and can be used as expected by ansible, ansible-playbook and other 'non-ee' versions of the software.

I've had a support case open with RH for nearly a month. This is preventing us from moving off of Tower.

Thanks