Unable to sign-in to Microsoft Defender on Android devices for child accounts

Thanks Emmanuel. I attempted to sign-in on their devices using my own account and got the same error ("Invalid license, please contact administrator"). I've signed in using my account on my Android phone and did not have this problem, so that account is working for login on another Android device. It looks like the problem is on those devices, but they are two separate models of Android tablet (one is a Samsung Galaxy Tab 8, the other is a Lenovo Tab M8).

I was looking through reviews for the MS Defender app on Google Play and noticed someone mentioning they were having the same issue as me. They blamed the issue on Android devices that are being managed via Google Family Link (for parental controls). Are there currently any known compatibility issues between MS Defender for Android and Google Family Link? My children's tablets (where I cannot sign in) are managed by Family Link, whereas my phone (where I signed into Defender with no problem) is not. Is that possibly a bug that we can raise to the Microsoft engineers working on Defender? Thanks for all your help.

Maybe you should try disabling first the Google Family Link temporarily then log in on the Microsoft Defender app on your child's devices then once successfully logged in on the Defender app then re-enable the again the Google Family Link.

If my suggestion above didn't work, I would suggest contacting the developer of the Defender app on the Google Playstore by searching Microsoft Defender from the Playstore and then clicking DEVELOPER CONTACT's email address atpandr@microsoft.com or leave feedback by rating the app.

Hi., this is an issue with IOS devices as well, I think from the last update. Unable to login to Defender App with Microsoft 365 family subscription.

Still seeing the issue on Android too. I've reached out to the developer email on the Defender app but haven't gotten a reply. Also opened two tickets with Microsoft support which said they would escalate the issue but never heard back on either of those.

I also have this issue on Samsung android devices of my children. I am subscribed to Microsoft 365 Family. I also noticed I can login their account in my device as a parent which I think is not restricted by the family link app. It seems that the family link app and windows defender doesn't go well together. Something that is restricting the google child account to work properly with Windows Defender.