I had success by going to an Apple store. To keep it brief (we did a lot of troubleshooting) in the end one of my AirPods (Gen 1) got replaced, which fixed the issue; however, the replacement did t immediately fix the issue.
Two other things we had to do was to ensure the AirPods firmware was up to date. You can find this when the AirPods are connected by going to: Settings>General>About>AirPods currently the firmware should be 6.8.8. If on a later version, plug the AirPods case in for about 30m while connected to your phone and on wifi. It should update automatically.
The next thing to do in a hard reset of the AirPods themselves. Hold the rear button for about 10s until the light goes amber. You’ll probably need to do it for both sets of AirPods as you may not know which set is not allowing the audio sharing.
Other than that, best of luck.