HI,
We pushed Microsoft MFA to everyone. We have a native exchange profile on all devices and noticed the settings for the exchange profile has OAuth as a selection which is what we need, and then see iOS12. I am guessing IOS12 is needed on devices to utilize OAuth for MFA to acutalize on the native profile. What happens to devices not on IOS 12. We are seeing weird issues, but I am not sure they are part of the this setting.