Yesterday I unpacked my new iPhone and the transfer from the old to the new device was simple and straight forward. So, I reset/deleted the old device. Wrong!
When I opened the security app for my banking account, it asked me to scan the QR code form the old phone. Hahaha.
It costs me 3 calls to some hotlines to get this fixed for all of my security apps.
So, take care and keep your old phone intact until you have tried all your old apps on the new device ;-)