Interestingly enough, Kodi’s developers haven’t yet published an official changelog for Kodi 18.4. Once again, we’re talking about an update that’s focusing on resolving technical issues and eliminating bugs, without introducing new features. And now, Kodi 18.4 is available for download for all the natively supported platforms. Back in late June, Kodi 18.3 was released, bringing a series of bugfixes focusing on the application's UI, PVR, and music functionality.
It looks like Kodi’s developers are following a schedule of releasing incremental updates to this application every two months.