Hi,
The KB4503294 released on June 18 belongs to the C version of Monthly quality updates. According to my experience, this needs to be released in WSUS for a while after the release. However, the C and D versions of Monthly quality updates may not be released
in WSUS. Please pay attention to the following article, which will update the latest added Monthly quality updates: "Description
of Software Update Services and Windows Server Update Services changes in content for 2019".
If you have doubts about the B, C, and D versions of Monthly quality updates, the explanation for this article can help you understand: "Windows
10 update servicing cadence".
Hope the above can help you.
Regards,
Yic
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