GPO "Block Signing into Office" does not working anymore

[henry162]

Hello,

i have and issue with a GPO setting to block O365 logins on our local systems.

For that I had already open a thread in the Q/A area but they forward me to this forum. (https://docs.microsoft.com/en-us/answers/questions/424955/gpo-34block-signing-into-office34-does-not...

We want to prevent using o365 accounts in Office / Outlook 2016.

Therefore we have configured the follow GPO "Block Signing into Office" with "None allowed". That had worked for the last times.

Since few weeks ago, it does not works anymore and every user can add a third-party O365 account to our Office suite.

The GPO are applied and the reg value are correct.

Are there any known changes by MS in Windows, Office or GPOs that have changed the behavior?
What can I do, to block the O365 cloud features on my devices?

We are running Windows 10 Enterprise v1809 and Office 2016.

Thanks,

Henry

[#2]

Any idea what could be the root issue?

[#3]

Hi Henry

Did you ever find a solution for this issue? I just realized that we have the same issue here and I am also not able to fix it :(

[#4]

@henry162 

May contact Microsoft support on the recent change in M365, btw below URL is worth taking a look about restriction:

https://learn.microsoft.com/en-us/entra/identity/enterprise-apps/tenant-restrictions