Ground Units Won't Fire in MP

[Spiceman]

Is anyone else seeing this?... I have a Blue unit and Red unit in each other's WEZ, the Blue is immortal and Weapons Hold (I want a sustained firefight). In SP, the Red fires on Blue. In MP with just me, the Red fires on Blue. But in MP with other people (4 in this case), the Red unit would not fire on the Blue unit.

 

Mission attached.

Caucusus_FAC.miz