I had an account with a bank that got bought. Always used the app, which worked fine, but I needed some document I could only get from the website. Go to log in and it gives me all sorts of weird errors. Support made me reset my password, all that stuff. I figured it out. Old bank would let you log in with email or username. New bank only let you log in with username, except it had dropped old bank’s username and put the email in the username field in their database. The website scrubbed emails from that field, and so it submitted a null username. The app didn’t l, so it let me log in. Weirdest issue I’ve ever had with a service and actually figured it out.
Hah, that sucks. My bank app let me log in without a password on my new phone just using the new fingerprint on the new phone, because I transferred the app from the old phone. Course, they recently limited cross account transfers to $100 because they’re seeing lots of fraud. No shit, right?