I've not changed anything in the SQL files. I checked the database and all fields on the phone confirmation form have 'type' params, however, the form object 'phone_confirmation' does not have 'type' field with 'POST' value similar to the one on timeline form. I'm not sure if this could be the reason!
I've now removed UNA and deleted the database, then reinstalled a clean new copy of UNA, however, I'm still getting the error once I turn on 2 factor authentication, even before installing any other modules.