Gmail filter applied without my knowledge

(Not sure if right place) my amazon account was hacked about 6 months ago. it has been rectified, but I noticed I wasnt getting amazon emails anymore, even the ones I wanted to get (order confirmations, cs chat, etc). I did some googling and apparently a filter was applied to my gmail that 1, marks the email as read, and 2, moves it into the trash, this has also been rectified. I know for a fact he didn't get into my email because of 2FA, but I did change my password to be safe. How was this able to happen?