ysugimura
Thanks for your responses guys.
I've never installed any amazon apps before that. Using amazon only on browsers. Today I reinstalled "amazon shopping" app and again it recognized it's me without login. So I uninstalled it.
BTW sorry I forgot to mention the following.
The first time I installed "amazon shopping" in owner profile with NO google things, it recognized it's me but it does not seem to work well without google things.
So uninstalled it from owner profile and installed it to second profile WITH google things. (Of course installed from Aurora Store) Before that I've never used any amazon things in second profile even in the browsers. This time it didn't recognize it's me and I should have enter account/password.
It's just for drawing one package from Amazon Hub Locker (without the app we can't do it, there's no other way), so after that I immediately uninstalled the app from the second profile. I will never use Amazon Hub Locker ever.
Today I also reinstalled the app in second profile. But it didn't recognize it's me and require login.
So strange. So my current guess is Amazon app can extract my account from the browsers. I know it's impossible but there's no other explanation for me now.