Pairing two AirPods from different sets

Hello. I have a left AirPods and right AirPod from different sets. Both are gen 2. I can pair each, individually, with my iPhone, but I cannot pair them together. This means only one plays at a time. I have tried resetting them according to Apple's instructions, and when I put both into the case (which is fully charged and plugged-in), the light blinks amber. Holding down the button on the case for as much as 15 or 30 seconds doesn't change the light.

I borrowed a friend's set of Gen 2 AirPods, and I can use his right and my left to reset, and they act like a normal pair. When I tried to use his left and my right, I get the same blinking amber light. This combination will not reset.

Please don't post links to these apple sites, and I have read and tried their instructions. If you have something new, I would really appreciate hear it.

Thanks

https://support.apple.com/en-us/HT209463 - Reset your AirPods

https://support.apple.com/en-us/HT209580- Identify your AirPods

https://support.apple.com/en-us/HT207012 - Charge your AirPods and learn about battery life

https://support.apple.com/en-us/HT207827 - Set up your replacement AirPods or charging case

https://support.apple.com/en-us/HT207010 - Connect and use your AirPods and AirPods Pro