Yesterday I have had an issue with computers not reporting to a newly installed WSUS server.
However targeting worked (computers where placed in the right Computer folders in WSUS), computers wouldn’t report.
When I looked into the ReportingEvents log in C:\windows\SoftwareDistribution folder, it showed a error “Windows Update Client failed to detect with error 0x8024401c”.
However this error wasn’t consistent (sometimes it did succeed, but it mostly didn’t)
It looked rather odd.
Browsing the web more people are talking about issues in IIS.
So this was the issue:
On Windows Server 2016, the “Private Memory Limit (KB)” was set to 1.8GB.
You should reset it to 0, so that WSUS can decide the memory usage of the WSUS Application Pool.
Once set, all issues with WSUS were gone.
Computers started reporting in immediately (off course this depends on the reporting configuration in your Group Policies).