Microsoft Authenticator problem on Android 10

Question

Hello!

I work in the IT department of a company and I'm trying to setup the Microsoft Authenticator app for a user's work account on their phone but I cannot get it to work.

I have successfully scanned the QR code, but in the validation screen right afterwards where it asks me to enter the 2-digit number shown on the computer, it shows a "Denied" toast notification right after I enter the correct number.

The phone is a 2019 Xiaomi Redmi 7A (Android 10).

The solution we have resorted to is to exclude the user from requiring the Microsoft Authenticator app and use their Phone number instead as an MFA method.

Any ideas why the Microsoft Authenticator app doesn't work?

If it is of any help, a similar situation happened with another user who has a Huawei phone (Chinese manufacturer again), but that one did not even have Google Services on it. The Xiaomi we're dealing with now does have Google Services and Play Store.