Please can any discussion around PIN lock go into one of the existing threads, as it tends to go around in circles and so clog up space 
https://community.monzo.com/t/app-security-and-privacy-fingerprint-pin-or-password/6218
https://community.monzo.com/t/an-update-on-pin-lock/45105
https://community.monzo.com/t/poll-help-us-make-a-decision-on-pin-unlocking/40939