SSO Login fails with desktop client

We have different issue with Nextcloud Desktop Client V2.5.1 SSO Login then this Issue but similar.

We are getting one step further.
We want to use SSO Login in our company and have integrated Nextcloud in our Acitve Directory over LDAP.
SSO is properly configured over ADFS.
The Option “SAML Login Only” is active.
We use Nextcloud Server V13 at the moment.

When we try to login from NC Desktop Client we get the following Screen after the user credential inputscreen.


Can someone please explain how exactly the user authentications with nextcloud desktop client works exactly when using SAML SSO Option only?


It look like SSO is currently broken based on the open issues. In the meantime I would set-up and use an app password as a workaround.