microsoft 365 OWA claims device is unregistered even though it is registered?

[LRSFC_DanJ]

Now that the new Cyber Essentials question set is requiring technical controls on BYOD device access to college resources, we're starting to test conditional access policies and compliance policies to achieve this.

 

We've got a conditional access policy set up (scoped to just me as I'm testing at the moment) which should block noncompliant devices from accessing Microsoft 365, and an accompanying compliance policy that requires a minimum OS version (Android in my case). I've registered my device using Microsoft Authenticator (didn't know it could do that, but apparently it can) and verified in the Entra ID backend that the device exists in Entra and is correctly showing as a personally owned registered device.

 

However when accessing the Outlook web app, I'm still getting blocked, and when I check the "Troubleshooting details" section it says my device is unregistered. How do I get it to recognise the device registration and let me in?

 

Also, before I registered my device, it was doing the same thing - how do I get it to prompt me to register instead of just blocking?