AIP, Purview, DKE problem (Double Key Encryption is obsolete and not supported?????)

Question

I am following the article below for deploying the DKE service. The configuration in the Purview section of the tenant is correct with label configured for DKE and the label published.

https://learn.microsoft.com/en-us/microsoft-365/compliance/double-key-encryption?view=o365-worldwide

The client (a Windows 10 VM, with Office 365 installed, AIP UL Clinet installed and registry settings applied) is used for the testing.

Also the DKE service is deployed and properly configured as an Azure Service App (also tested using the PS script)

The protection of the documents in the Windows 10 VM, was (theoretically) taking place without problems, since the label published was available -everything was running smoothly, OR SO I THOUGHT, please see the next paragraph.

While trying to change the source code of the DKE service (to accept users from Azure AD groups instead from an on-premises AD domain) I tried to attach to the process to check my implementation. I was extremely surprised that I could not attach to the process, however the Protection on the VM was still working. That's when I suspected that something was completely wrong and I decided to stop the Service App. What I found out was that the Windows 10 client was still protecting documents without taking into account the DKE configuration in Purview.

I opened a ticket to the M365 support, thinking that this could be a M365 problem. I also opened a ticket to the Azure support, because it can be an AIP problem. None was able to support, instead they re-directed here to ask a question.

Any ideas on what and how to troubleshoot will be greatly appreciated.