This has happaned on a number of occasion and is very random when it does happen.
I login to the app via magic email, set up a PIN and allow Touch ID.
I close the app (without logging out) just by Home button on iPhone.
When I go back in I am randomly confronted by one of two things:
- I have to use touch ID to access the app (all good)
- I have to enter my email address and repeat the magicmail and PIN process.
I’m not doing anything different each time.