New iPhone 7 asking for password for my old defunct Apple ID.

I bought a brand new iPhone 7 from Verizon Wireless for my daughter to replace her 6s. She wanted to pick it up at the store so it can be activated because she isn't very "tech savvy". We never had a problem with activation at our usual store where we live, but this store near her job and school had this particular phone in stock and they wouldn't activate it.

Anyway, long story short, after about 4 hours and many tears, she texted me asking for my Apple ID password because new phone kept asking for it and she couldn't finish setting up the activation. I gave her the password and she kept saying that it's wrong. Turns out the Apple ID was my old ID that I haven't used in YEARS. I had updated the ID to my current email address years ago and I haven't used that ID in I don't know how long. After much frustration she had to take a trip down to the Apple store (since the Verizon store is now closed) and they said it's something with an old app or media that was purchased using that ID and it needs to be deleted.

Really? They somehow fixed it and everything was find up until about midnight when it popped up again asking for the password.

This isn't some random Apple ID I've been reading about. It's my old one. And my daughter used her own Apple ID on her previous phones. So I have no clue why all of a sudden this came up.

How do we get this to stop? I think she might need to make another trip down to the Apple Store again and see what's up.

This is very frustrating. I paid a lot of money for something that has a glitch and that shouldn't be. How do we get this to stop??? Can I just go through my old phones and whatever and start deleting things and hopefully they'll delete from the "cloud" and stop sending error messages to her new phone? I have no clue......