Only the first AirPods Pro I put in my ear works
I had the exact same issue with my right AirPod and I bought them about 2 months ago also!!!  I think there may have been a bad batch of AirPods Pro.  I called apple and they sent me a new right AirPod and they work perfectly now.  I suggest doing the same thing.
Also, when you get the replacement, I had to unpair, then reset the AirPods a couple times before it would connect to the new one.