I think the update to the RPG model broke the ability for the HECU to use it, as evidenced by this map.
Perhaps I’m doing it wrong, but I took an npc_human_grenadier and manually assigned him the weapon_rpg. I end up with the same effect as the example map. He comes out with the RPG, but he can’t seem to fire it. He plays firing animations, but nothing comes out. Screenshots for that map show that this used to work at one point not so long ago, which is why I think it’s related to the RPG model’s update.
This was brought to my attention when it was suggested to use an RPG soldier for a scenario and I wasn’t aware they existed. Ihonnyboy pointed me to the above map which contained them, and that’s where I noticed this issue.