I got a similar problem:

- "check for updates" --> KB4476976 and KB4481031 downloaded and installed

result: 0x80070643 for KB4476976 and 0x800f0922 for KB4481031.

- new "check for updates" --> KB4476976 and KB4481031 (already loaded) installed

result: 0x800f0922for KB4476976 and for KB4481031.

- new "check for updates" --> KB4476976 and KB4481031 (already loaded) installed

result: 0x800f0922for KB4476976 and for KB4481031.

I had runned: (Windows Powershell as Admin)

DISM.exe /Online /Cleanup-image /Scanhealth

DISM.exe /Online /Cleanup-image /Checkhealth

DISM.exe /Online /Cleanup-image /Restorehealth

SFC /SCANNOW

--> everything OK.

I tried an advice given in french forum:

"- run "Services"

- stop "Windows Updates" and "Ciphering services"

- delete content of folder C:\Windows\SoftwareDistribution

- in "services", restart "windows Update" and "Ciphering services"

- download update from https://www.catalog.update.microsoft.com/Search.aspx?q=KB4476976 and

install it manually".

In fact:

- I stopped "Windows Update" ("Ciphering services" was not active),

- I renamed "C:\Windows\SoftwareDistribution\Download" to

"C:\Windows\SoftwareDistribution\Downloadxx", and re-created empty folder

C:\Windows\SoftwareDistribution\Download" -> this forces Windows Update to download

again corrections,- I restarted "Windows Update" service,

- in Windows Update, I clicked again on "Check for updates":

-->

- Windows Update found KB4476976 and KB4481031,

- Windows Update downloaded KB4476976 and KB4481031, and installed them successfully,

and after restart my Windows 10 is at level 17763.292.

I will never know why installation has been successfull at 4th time: is it because KB4476976 and KB4481031 have been downloaded again? And if so, why? Does it mean that Microsoft has changed something? hmmm...!

Good luck!