If you're using Luma Updater 2.1.2, you cannot update to the latest hourly build. If you want to update to the latest hourly build, you need to use Luma Updater 2.1.1, or you can do it manually by downloading the hourly boot.firm and putting it onto your SD card.
I don't see any immediate reason to update to an hourly build. Stable version 8.0 runs just fine.