Office 365 installed itself over Office 2019 The Click-2-Run packages pull their own updates and do not receive them via Windows Update.
The aforementioned Office packages are available for installation from Microsoft via a click-to-run installer package. Microsoft Office 365, on the other hand, is Microsoft's subscription model, which has to be renewed annually. Microsoft Office 2016 and Office 2019 (and also Office 2021) are packages whose license is purchased once and is then valid indefinitely (so-called perpetual license).
