Endless loop of Apple ID Locked
I have an Apple ID that I created that does not have a credit card associated with it. I know the password and can answer all the security questions. I can login to the iCloud website with it, but not iCloud on the iPhone. The Apple ID doesn't work in the app store to download a free app (I have tried a couple solitaire games and password utility) either. As soon as I click on the free app it asks me to provide the password. As soon as I provide the password it says "The Apple ID has been locked for security reasons. To unlock it, you must verify your identity." I have gone through the unlock process several times, both resetting the password be email and resetting the password by answering the security questions. This process is successful in that the new password does work when I login to the iCloud website, but it still won't work in the app store. It continues to tell me my Apple ID has been locked for security reasons.
I have searched for a solution to this and found similar issues, but none of those resolutions either pertain or work for this issue.
iPhone 6s, iOS 11.2.6