All of those of us who have forced IP-adress changes ever 24 hours (many european ISPs do this) and have 2FA enabled for the MS account are affected by constantly having to use an Authenticator app to verify login everytime we want to login to https://www.minecraft.net/en-us/msaprofile
Even when we tick the box "remember this device" during login.
This is a security feature so hackers can’t clone you’re cookies and log in to youre account without password or 2fa when they obtain access to youre browser cookies (At least I think that)