Why does a pop up show and ask me to login to a weird iTunes account that isn't mine? The phone was in a sealed box so I know it wasn't a used phone.
There have been posts about this happening, when other people used someone's computer/iTunes and when there have been apps/music purchased by others in the same computer/iTunes.
Do you have anyone else's content in there, or where you gifted any apps/music?
Sent from my iOS ecosystem!
Have you checked all the apps in iTunes? There may be an app from a different account, and it requires you to update it whenever it gets synced over to your phone.