Hello,
I also have two of these headphones. I haven't documented this in detail, but I also noticed that they empty very quickly, even if you don't use them at all.

Yes, I am also aware of the problem
I got it new, set it up, charged it and put it aside.
After 2 weeks I wanted to use it for the first time, I was in the tram and opened the lid and everything was dead.
Nothing worked anymore - big eyes, angry eyes
Well, that can happen, however.
Charged it up at home and everything was ok.
Then the same thing happened again, after about 2 weeks I wanted to use it - dead!
Called customer service, got a tip to reset, didn't help, after a few days there was still a visible drop in the battery.
Called again, was supposed to send the handsets in.
Came back after a week - NO error.
Of course the error was still there.
Called again, was told to send in the handsets.
Came back after a week - NO error.
Of course, the error was still there.

Funnily enough, Huawai can actually NOT say how long the handsets can remain in the box ready for use.
From this, I actually conclude that no noticeable discharge is actually planned here.

I suspect that many people have this problem but do not notice it if they use the handsets every day.

There are 2 possibilities;

We have faulty earpieces or the case
It is "normal" and the earpieces have a design fault and something does not switch off even though the case is closed and is somehow still on standby, I can't explain it any other way, there must be a relatively high current flow to drain the earpieces and the entire case within 10 days, this is not self-discharge through buffers or something.
Something like this should easily last a few months.

Fun fact:
I think my Huawei P30Pro has a standby time of about 20 days.
That means the phone is switched ON and running.
The fact that my switched-off headphones only last 10 days is absolutely unacceptable.

In principle, this almost means that I have to keep the case connected to the charger like a fire engine so that it is actually 100% full when I need it.

Ridiculous!

But I'm sticking to the topic. So far I had always held up the flag for Huawei, but here they fail in terms of hardware and especially support, which neither knows how long the time in the case is or the technicians who see no fault here and send the device back.

LG

I also have these headphones, use them every day and then put them back in the charging case. They easily last a week in the charging case and the battery of the charging case is still at about 50%.