https://wccftech.com/windows-10-1809-bugs-admin-account/

Apparently, we aren’t yet done with the Windows 10 October 2018 Update issues. A fresh new problem (or more like a nuisance) has surfaced thanks to an update posted by Microsoft Taiwan. In a blog post, the company writes that if you are upgrading to the latest Windows 10 1809 from version 1803, “the built-in Administrator account is inadvertently invalidated.”

Definitely not a big issue like the ones we have seen previously, but it could turn out to be an annoyance for some. The company further adds (via TechDows) that this latest one of the Windows 10 1809 bugs appears when both of the following conditions are met: