I update my Macbook Pro* today to macOS Mojave 10.14 (18A391).
I have a Magic Mouse that I've been using for years and that has so far always worked.
However, now the right click with that Magic Mouse does no longer work. I can do a right click with two fingers on my Trackpad but not using the mouse.
I checked the settings and Secondary click is enabled.
Double-tap to zoom does work fine.
* MacBook Pro with Touch Bar (13-inch, 2017, Four Thunderbolt 3 Ports)