Very interesting. On my second machine that gave me this issue and where I didn't go through resizing the recovery partition, your post made me look again after multiple installation failures. And what do I find ...
'You're up to date', and under the installed updates:
You can see the multiple failures, yet...
But going to check again, the machine is again attempting to install KB503441 ... having failed 6 times previously from the above history, and then reporting all ap to date 🤦♂️ Something seems very wrong. Either the machine is, or is not up to date.
And the re-attempted update resulted in
And the history confirms the failure...