Paul:
I can’t help but think the controller is defective. I just sent back a DJI Smart controller just purchased from a seller on eBay as it had defective sound and the installed dji Go4 was not connecting (similar to yours).
I would return it.
This is what I do, too. I use Vifly beacon/beeper on top and run nav lights, too. The Vifly beacon is the big rig-saver ... it has saved several drones and fixed-wing AC for me. Best $15 you'll ever spend.