Sonos Ace Ultra: left ear cup rattle and short battery life—anyone else?

Has anyone else experienced either of these issues with their Sonos Ace Ultra?

Mine developed a noise/rattle in the left ear cup, as though something inside was loose. I wondered whether it might be the battery, but that’s only a suspicion—I haven’t opened them up to check.

Battery life was also disappointing: roughly 11–12 hours, around a third of the advertised 35 hours.

They’ve now been posted back to Sonos for replacement, so I’m not looking for troubleshooting at this stage. I’m just curious whether anyone else has noticed similar issues, or whether I was unlucky with my particular pair.

If you’ve experienced either, I’d be interested to hear whether a replacement resolved it.