How to resolve one Airpods Pro 2 bud not working while pairing two sets with Avantree Relay?

There are two methods to fix the issue of only one bud working while pairing two sets Airpods pro 2 with Relay.

Method 1 - put the no sound bud back into its case for a few seconds and then taking it out. This should result in all four buds working well.

Method 2 - leave both pairs of Airpods Pro 2 inside the case for pairing. Once paired, take the buds off from the case AFTER paired them both with the transmitter successfully. 

Upgrading the Airpods Pro 2 software version from 5B.58 to 5E.135 is recommended as it significantly improves the success rate of normal pairing.