Sorry to bring up the old post. Like you, I was lucky to have my 1000XM4 replaced few months before warranty expire, but now, my right earbud drain from 90% to 20% less than 20 minutes. left side seems still ok but definitely less than 6 hours. I would not consider anymore Sony wireless earbud. I think XM4 is last batch Made in Malaysia, XM5 is now made in China?

I used to be active in Sony Community Forum on this 1000XM4 battery drain issues... but Sony had closed down this community forum.