Authenticator on iOS - No longer pushing notifications...instead, app shows a number but no where to input it

Question

Within the last few days all of my iOS users are having issues with MFA on their Microsoft Authenticator apps. The app no longer sends a push notification for MFA. Instead, it asks you to input a single 2-digit number that appears in a box into Authenticator, but there is no means to input the given number anywhere in the app. I have never seen this type of authentication request until recently.

I have checked multiple user accounts and their notification settings are correct.

There has been no change to our policies or system profiles.

This is affecting new and currant users equally.

We do not use full MDM on our user's iPhone, just an MFA policy tied to them that allows access to company e-mail via Outlook.

The same issue is appearing if an MFA request is sent from a user's PC

I am seeing a sign-in error in Azure that states -

Assertion failed signature validation. Possibly because the token issuer doesn't match the API version within its valid time range, it's expired or malformed, or the refresh token in the assertion is not a primary refresh token.

I am also wondering if this is related to the Intune authentication issue with iOS devices I saw being reported earlier...both issues seemed to pop-up at the same time.