Using the map mods, so that could impact this. However, the soldier is positioned on a valid tile and the effect is limited to the first turn, so I'm not sure why a map mod would cause the loss of actions for one turn. The second and following turns the soldier is able to act normally.
I've seen this twice with LW 1.1. Save available for second time.
I never observed this with vanilla and, FWIW, LW 1.0 before the update.