Hi @Sokoban ,
Thanks for your feedback. We're glad that the question is fixed now. It's appreciated that you could click "Accept Answer" to the helpful reply, this will help other users to search for useful information more quickly. Here's a short summary for the problem.
SCCM - Surface drivers do not show up in "All Software Updates".
On the WSUS server, navigate to %SystemRoot%\system32\inetsrv. Create a new and emtpy w3wp.exe.config and add the below lines:
Finally, restart IIS and wait for synchronization.
Thanks again for your time! Have a nice day!