KB4494441 for Windows 10 version 1809 may install twice to provide new speculative side-channel protection for the most recent Patch Tuesday update as shared below.  So far, this appears not to cause any Windows integrity issues, other than additional processing time:



Reports are coming in that this week’s security update for Windows 10 version 1809, KB4494441, may install twice on devices running that particular version of Windows 10. Microsoft released KB4494441 for Windows 10 version 1809 on Tuesday as part of the company’s monthly patch day. The May 2019 update for Windows 10 version 1809 patched a critical security vulnerability in Windows 10, enabled protections against a new class of speculative side-channel vulnerabilities, and enabled Retpoline to optimize protections against the Spectra 2 Variant.