I am using Samsung Galaxy Note 8. Once my battery reaches 20%, it quickly turns to 2% within a blink. Any idea !

I an using Note 8. Once the battery reaches 10%,  the mobile switch off and doesn't turn on. When I insert wire to charge, the display shows mobile is charginf from 0%. My mobile is 1 year old. Any help

I am using Samsung Pass in Note 8. Samsung pass is not able to save password of many apps like yahoo mail, facebook, etc. It gives saving option but doesnt work. See attached file.

Just formatted my mobile and Not able to update Bixby . Screen shot attached.