Clear the Windows Update Download cache

You probably need to clear the Windows Update Download cache (I had to do this to get 15046 to appear).

net stop wuauserv
cd %systemroot%\SoftwareDistribution
rmdir /S /Q Download
net start wuauserv
net stop bits
net start bits
net stop cryptsvc
cd %systemroot%\system32
rmdir /S /Q catroot2
net start cryptsvc

Reboot.

https://answers.microsoft.com/en-us/insider/forum/insider_wintp-insider_install/install-of-15042-reboots-at-71-to-15031/a640c8f4-b93c-46fb-9aee-4d302f00eadf