The mobile app definitely has a very bad UX.
First off, the landing page of the app is not clear on whether it is a login screen or a register screen. If you have many email addresses and forget which one you used, will end up running in circles being prompted to create a new account using another email address or your phone number.
If you do remember which email or phone number you used, but forget your PIN, good luck because you won't have an easy time resetting it. They send you a code to your email for verification to login which is great. But I still can't reset my PIN without entering my old one (which I don't remember).
So yes, very bad overall UX considering your issues on top of these which are already bad.
The app works fine, serves a good purpose, and is developed well. But the design of it is very poor and I know I'm not alone in feeling this way.