Nope, you didn't miss a secret run toggle in the options because it doesn't actually exist. We cover every reason for slow movement in Pathfinder: Kingmaker -- and how to fix it.
All the core classes from tabletop Pathfinder made their way into Kingmaker, along with a few Advanced Player's Guide classes and a host of archetypes.
Pathfinder: Kingmaker just released today and some players are already running into a load screen bug. As the devs work on an official fix, here are some tips that might get you around it.