Not sure what you are saying. I was a Three customer who has swapped to the 'sister' company Smarty, never had this issue with the Three app. 90% of the apps I use remember me and I don't need to log in every time.
I use online banking on this phone and 99% of the time use fingerprint login. I don't have to re-enter username and password every time and then authenticate with a one time code.
