Airpods connect, but sound output doesn't change

Hello everyone,

My Airpods have been doing a weird thing. When I take them out of the case, the Bluetooth connection to the phone is made, but the audio output doesn't change - the audio continues to play from the iPhone speaker.

I can still manually select the Airpods as the output device through control center or the Music app, but then the sensors on the Airpods stop working. When I remove one or both buds from my ear, they continue to play even after putting them back into the case.

I've tried resetting and re-pairing the Airpods, resetting the phone network settings, resetting all iPhone settings, and I've taken the Airpods to the Genius bar and received new ones. The problem goes away after doing these things, but comes back soon after.

Anybody else have the same issue?