Agent Buzzkill

After not playing the game for a while I gave it another go with the scenario called Absolut Panic. I thought I would have fun playing as partisans palying against veteran German troops. no such luck. The AI fails to attack me. It seems to move the trucks a little but none of them make any advance in my direction. I played defensive scenarious before and AI always makes some kind of an attempt at an attack. What could possibly be wrong?