activation lock cant be unlocked on iphone 8 plus

i guess i had "find my phone" on. i went to icloud through my pc web browser and removed the phone from my account whitout turning "find my phone" off. So after opening itunes and resetting it, the activation lock wants me to sign in to my account but wont accept my credentials. for the longest time i thought i was going crazy and i forgot the password for my apple id. but ive done a password reset and i am able to sign into my account. but still cant unlock the iphone using my apple i.d and new password. My husband thinks i must have created a new apple id for the phone. which is impossible. how do i know this? because around the time, my husband had bought me an apple watch, which i had also added onto my account. and when i do sign-in into my icloud. the watch is still there in my devices. so i know this is the correct apple id.