Outlook with Exchange 2019 CU13 & ModernAuthentication

Greetings everyone,

I am currently trying to get ModernAuth running in conjunction with Exchange 2019. I used these instructions for this:

https://learn.microsoft.com/en-us/exchange/plan-and-deploy/post-installation-tasks/enable-modern-auth-in-exchange-server-on-premises?view=exchserver-2019

I am currently failing at the Outlook point. The client opens, the setup of the mail address starts, the ADFS login window opens, user data is entered correctly and after a short time I end up back in the setup and the game starts again.

Eventlog:

Name of the faulty application: OUTLOOK.EXE, version: 16.0.17830.20138, timestamp: 0x66aaad8c

Name of the faulty module: mso20win32client.dll, version: 0.0.0.0, timestamp: 0x668f31af

Exception code: 0x01483052

Fehleroffset: 0x000000000031782d

ID of the faulty process: 0x0x16CC

Start time of the faulty application: 0x0x1DAF3BB250FB675

Path of the faulty application: C:\Program Files\Microsoft Office\root\Office16\OUTLOOK.EXE

Path of the faulty module: C:\Program Files\Common Files\Microsoft Shared\Office16\mso20win32client.dll

Berichtskennung: 6232fab8-77a5-441c-a204-b9db6bebfe1e

Full name of the faulty package:

Application ID that is relative to the bad package:

ADFS trace:

An OAuth authorization code: 'q5q4BILC3AgCAPklqlJhAv28gd0' was successfully sent to Client: 'd3590ed6-52b3-4102-aeff-aad2292ab01c' with redirectUri: 'ms-appx-web://Microsoft. AAD.BrokerPlugin/d3590ed6-52b3-4102-aeff-aad2292ab01c' for resource 'https://(ExchangeServer).zentrale.etask.de/'. The user is 'ZENTRALE\exchange-test-user

' on the device '' if device claims exist. The client IP is '192.168.10.53'.

Any ideas?