Respectfully, it's not (only) the beta plugin.
There's some issue with the general release IMO. I had problems initially and then managed to get it working, then had problems again and then cleared "persistence" and started working (but maybe that was coincidence).
It shouldn't be this hard to get it working. Every other add-on that I've purchased for MSFS that uses simconnect (eg Navigraph, AxisAndOhs, SpadNext, PMS50 etc etc) works flawlessly the first time!
Maybe you could add more detailed logging that might help people narrow down the issue? A lot of people seem to have issues.
I know AirManager also supports XP, FSX, P3D etc, but I think I recall you saying you don't own MSFS? You wanted me to share my PC via remote desktop. Maybe I was mistaken. But I would think you need to test AirManager on MSFS too, not just assume it works without issues. Forgive me if I have this wrong....
Anyway AirManager is fantastic, but these connection issues are frustrating.
(ps: I've not used AirManager in a couple of weeks so I'm not sure if there's been any updates and if the issue has been resolved)