For everyone that reads this in the future, I purchased Airpods Pro which had this issue on second use. (first use, it went to 100%). on the next uses, the left pod could not go higher than 70% charger. and when using it, 70% of charge finish in just 30min, where the right side was normal.
I called apple, at first, i was told that i have to use my airpod for 1 week and battery will settle by itself. I told them I “want” to use it, but it do not allow me. it keep go off after short period of time. so they agree to exchange, but apple exchange would take 14 days where I am.
so I went back to the same e-commerce website that I purchased it from (tiki.vn), they send a bike to collect airpod from me, they investigate and after 3 days, they send another bike to deliver a new box to me (completely new). new box does not have this issue anymore.