Same here. Felt like I was going insane! The support person ran a remote diagnostic and declared the battery health is fine.
But, as I explained to them, I was so fed up with the battery draining that I charged to 100% and manually powered off the iPad...after month or so, I turn it on and the battery is 30%!!!
But iPad Air 5 does not record this data with timestamps - so it is hard to prove this happens.
In countries where Apple sells the products at even more inflated rates, you really do feel ripped off. In this region - for instance - the exchange rate's around 80. But Apple multiples USD rates by 100. (They manufacture devices in the region!!!)