Interesting to hear you have exactly the same usage of the module as us and that you’ve tested everything and found it working.
In July 2019 I was having a right palarva trying to get something working
Bug report here another here and another forum post here
It’s true I’ve learned a lot since July 2019 about how FreePBX and Asterisk work, but I certainly had a lot of bovva! 
It’s mostly working now, just a few niggles around visual voicemail and the Digium Phones, but as I said, presence and phone info in the Digium Phones tab don’t populate