And if it would be so trivial and obvious, I wouldn't go to all the "troubles" with the simple instalation. Who knows, what fixed the darn thing, whether it was the Service Pack itself or the Symbols.

If you see the You’re not up to date message on the Windows Update page in WIndows 11/10 Settings but no update is available, restart your system and try again. If this does not help, use these fixes: ...

Windows updates can seem stuck, but they may be running especially slow — if yours is truly stuck, there are ways to troubleshoot. Beware of interfering with an update too soon; if you stop an update ...