support.microsoft[.]com/en-us/help/4494441/windows-10-update-kb4494441
Microsoft says *some* users report, but it's every time for me. The update only shows up the 2nd time if you manually check for updates [click the check for updates button], &/or if you bother to check the Windows version number [I never do], so most people running win10 1809 are probably unaware of it. And the update does not get applied the 1st time you install it, despite it showing successfully installed the 1st time round.