Windows Server 2025 24H4 is not useable anymore after Nov. Update KB5068861

Hello,
currently, on several Windows Server 2025 Datacenter systems, version 24H2, I am experiencing severe issues accessing network resources after the automatic installation of update KB5068861. This affects network access from Windows Server 2025 24H2 to Windows Server 2025 24H2. Access from these servers to older Windows Server 2016 systems works without any problems.
When entering a UNC path—whether by name or by IP—I am always prompted for my credentials, even as a domain administrator. No matter which credentials I enter, I always receive the message that the username or password is incorrect.
Under “Change advanced sharing settings,” the two switches “Network discovery” and “File and printer sharing” are set to OFF in the domain network after the update. Re-enabling these two options, which are normally enabled by default, does not improve the situation.
Since this patch, I also have an issue on a Windows Server 2025 RDS host where a logged-in user cannot type in the “Search” field. Additionally, the performance on the RDS host feels extremely sluggish.
Unfortunately, uninstalling the patch is not possible. The patch KB5067036 is not installed.
I have already performed a restore to the day before KB5068861 was installed, but without the desired improvement in performance. Even after the restore, I still cannot access the network via UNC through File Explorer as a user. In the search window, I can access via UNC path. As an administrator, access via UNC path works both in File Explorer and in the “Search” field. Everything worked fine before 11/11/2025.
Has anyone had similar experiences or already found a solution? Is a patch for the patch planned?
Currently, troubleshooting feels like groping in the dark! In this state, the 24H2 server is no longer usable.

What was Microsoft even thinking, releasing such faulty patches—and for weeks now? Is there still any quality control at Microsoft for such critical updates and patches?

Thanks for every support, idea, and comment.