Andreas☀️
Similar issue here.
(update to?) iphone xs/i.o.s 12.3.1
When I started (sunday) bunq, I needed to give in my phone# and login with pin and passfrase, (passfrase was wrong, but I doubt that as I choose an easely to remember one and checked this with 'pwd visible'), so I did a pwd reset, with the 1 cent transfer. Everything worked fine, except for my mood (seriously annoyed).
Today I did receive 2 messages from transactions, when I wanted to login it gave the error "server signature is invalid".
An other issue: you cannot post to the forum if your app does not work. So an 'anonymous' option would be a nice feature.