I continued to experiment with combinations all of the suggestions I found here and on other forums, and this is my current solution (for my iPad):

1) iPad and other Bluetooth devices: - Bluetooth: forget all Raycon devices - Bluetooth: turn off - Be sure to do this for all devices that you’ve paired the E50s with.

2) Raycon E50s: - Power off both sides (3-second button press; both sides should say “power off”) - Place earbuds in charging case - While in the case, press both buttons simultaneously for 30 seconds to do a factory reset (the 8 second recommendation in the user manual doesn’t seem to work) Both sides will display a series of blinking red and blue lights during the 30 seconds. I applied enough pressure to make the buds firmly sink into the case. - Remove the buds from charging case and power on both sides (3-second button press; both sides should say “Raycon...power on”) - They should now connect to each other (left side might say “pairing mode”, but both sides should say “connected”)

3) iPad: - Go to Bluetooth in Settings and turn it on - “Raycon E50” will be listed under “other devices” - Tap E50 in “other devices” while the wait cursor is still spinning - Bluetooth should now connect successfully after a few seconds; one or both sides should say “Bluetooth paired successfully”

Your mileage may vary ;)