Just putting this out in case someone's keep track of failure trends. I have already opened a case.
Received my Pixel Buds 2 today, got the fast pair notification when I opened the case, and followed Pairing and Setup wizards.
Left bud is not detected, even though it is reporting battery life. Right bud plays audio, notification music when inserted into ear, responds to touch gestures.
Had pairing forgetting, power-cycled phone. Reset pairing on the case. Same outcome.
Forgot pairing again, shut off phone. Reset buds in case, paired them with my Pixelbook, same behavior - left bud non-response, right bud operates as expected.
Pixel 3, Android 10. I reported OS Version, Google App and Google Play Services version to CSR. L/R and Case are all on Firmware 225. Firmware update says it's available, but I left them charging in the case with the case plugged in, my phone next to it, firmware never updated.
Reading through some of the Device Performance threads, there are similar situations out there, with the left bud specifically. Will wait for a few days to see what they come back with, but am on the fence about just returning it at this point.