Problems with Intune and certificates

Hey all,

we want to change our MDM from MobileIron to Intune.
So far the Microsoft Endpoint Manager in the Azure AD is also configured and working.

Unfortunately the transfer of wifi SCEP certificate just does not work.

We have created a virtual machine, installed there a NDES server, IIS, everything needed for the role and the Microsoft Intune Certificate Connector.
So far the connection is fine everywhere. It shows green in Endpoint Manager, everything is fine in Application App Proxy as well.

According to the log, the iOS devices are also requesting on the server (2022-05-10 12:21:57 fe80::7d45:33f6:ec33:eb94%6 GET /certsrv/mscep/mscep.dll/ operation=GetCACert&message=SCEP%20Authority 443 - fe80::7d45:33f6:ec33:eb94%6 profiled/1.0+CFNetwork/1331.0.7+Darwin/21.4.0 - 200 0 0 0).

And then everything stucks.

Microsoft Endpoint Manager just shows an error.

There is no log on the virtual machine - just nothing.

I have already opened a ticket at Microsoft, but I am waiting there since 2. May 2022 for a reasonable feedback. The first level support always asks for new screenshots and/or logs, which unfortunately do not exist like that and I never get an answer to my queries.
Another big problem is that the documentation refers to the old connector version and so I can't find any error anymore.

Does anyone know this problem or has an idea where I can start?
I am desperate.

Thanks to you

Kind regards 

Steffi