Nothing is stupid! I just really appreciate all the ideas / input in all honesty (especially after being stone-walled by DJI "support").
I have plenty to try now at least (feels like progress in itself), and at least know what i am seeing...
Many of Mavic 2's were purchased with the RM500 Smart Controller, so that is the "original" controller. That's how I purchased mine new from DJI. I know you were also able buy them with just a basic "plain Jane" controller as well, but many folks...
You mentioned Google play, which I can't even figure out why it would be in an RM500. I have a mavic 2 & RM500 controller that I've had since it was new, and it never had Google play. The only apps in it was a generic browser and Amazon Appstore...
I think 3rd party is probably your only choice at this point. I've had two:
The one from 'Satonaka' fit and worked, but the cells overheated a bit. Still, there was no swelling. (link here)
The one from 'XDJXWJN' fit, worked, and stayed at a...
You need to download the correct app right from DJI'S website, nothing out of the playstore. Here's the link to it: Phantom 2 - Download Center - DJI Phantom 2 - Download Center - DJI