Why are my characters not switching to Dynamic mode?

Always remember that the Physicalize Behavior set the physics mode when it stops. When creating a physics setup it is really important to check that all triggers are set correctly. The easiest way to check if triggers are correct is to select a character in the viewport in order to activate the Visual Debug and open the Behavior Editor to see which behaviors are currently running or not.
 
Here is how to setup the physics in 5 easy steps to set the entities flying.
  1. Make them move using either Locomotion, Motion , Navigation... behaviors.
  2. Add the Physicalize Behavior in parallel with the current motions.
  3. Add a end trigger to start the physics and make sure the Parrallel operator will stop as soon as one behavior ends.
  4. Add a Force Behavior after the Parallel Operator and do not forget to set its Stop Trigger
  5. Add a Physicalize Behavior set to dephysicalize and set its Start Trigger condition