Thank you. I think this might be a false positive, since I have seen some reports:
https://learn.microsoft.com/pl-pl/answers/questions/6057218/missing-source-files-error-0x800f081f
I recommend not taking any action, as it might be induced with the update.
I hope this information helps. If you have any more questions, don't hesitate to reach out. Wishing you good luck!