MS Authenticator defaults instead of DUO

Anyone encounter the issue where MS Authenticator keeps defaulting as authenticator app when setting up 365? Prompts to “Open Authenticator”, click/select it, then loops and forwards to DUO to complete authentication. If I remove MS Authenticator app, it works fine. Reinstall from Apple store - no accounts added, defaults again!! Issue occurs on iOS / Android devices that have MS Authenticator app already installed. I sincerely appreciate any help on this.
authenticator

Hi RigoV,
Welcome to the Duo Community.

I have no elegant solution for this. Much like the way you can define what application is used to open a .pdf file in Windows. It depends on iOS or the Android OS adding functionality for you to be able to define a default authenticator application manually. This would be the same way you define a default browser on your phone to use Chrome rather than Safari for example.

From my research such functionality both in iOS and Android does not yet exist at this time, and you will either need to remove the application you do not use, or live with the extra steps.

From your test results so far, I suspect iOS is simply using the last authenticator application installed as the default, but i have not tested this my self to confirm.