What is the correct process to add an Office 365 account with two-factor authentication?

Hello,

I recently enabled 2FA on my Office 365 account and it works perfectly. I use the Microsoft Authenticator app on my iPhone.

However, I wanted to confirm that I have the setup on my iPhone correctly when using the iOS apps for which I sync data (e.g., Mail, Calendar, Reminders, Contacts). That is, 2FA works with the iOS apps, but every few hours or so, iOS will require me to re-log back into my Office 365 account and re-do the 2FA. Is this normal or is there something wrong with my Office 365 account setup on my iPhone?

This nuisance does not occur if I use the MS Outlook app, for example. It never loses its Office 365 account connection and requires me to re-authenticate.

Thanks!