Description of problem: I upgraded my Dell XPS 9550 from Fedora 27 to 28 (wipe and fresh install). After upgrade there is no middle click or right click on the track pad. This is true in both Wayland and Xorg sessions. Looking at the libinput events, I can see there is left, middle and right click events but somehow at the Gnome level the middle and right click don't register. Version-Release number of selected component (if applicable): Fedora 28 Beta
It seems this was the result of new defaults. I was able to get right and middle clicks back by going into the mouse section of GNOME tweaks and selecting "Area" under mouse click emulation. So... two things, I had to start GNOME tweaks to fix this not the main control center. And even within there, this is was very counter intuitive.
For the record, this post explains the changed defaults. http://who-t.blogspot.com/2018/04/gnome-328-uses-clickfinger-behaviour-by.html