Hi @Jason Kowalczyk ,
Yes, Azure Security default may affect mobile devices. According to similar situations in the past, as Andy said, reconfiguring the account profile is a very effective way.
For how to set the login behavior of different versions of Offcie client apps, this official article gives detailed registry keys and their impact. Please refer to: How modern authentication works for Office 2013, Office 2016, and Office 2019 client apps
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