It turns out there's a setting in the game that limits the number of moves you can make so you always have action points available to fire. I think pressing either Ctrl or Shift on the keyboard toggles between the modes.

It turns out there's a setting in the game that limits the number of moves you can make so you always have action points available to fire. I think pressing either Ctrl or Shift on the keyboard toggles between the modes. I just happened to be near an obstacle when I stopped moving so that was a red herring.