No mods or optional DLC apart from Western Sahara were loaded. The IED UAV (UAV_02_IED_lxWS)'s explosive grenades will not explode. I tested every side's IED UAV, in a mission, and in the editor both from around 10 to 200 meters high. They just impact the ground and then despawn like under barrel grenades do when they are fired from too close. Smoke grenades will release smoke like normal. HE and smoke grenades will both explode if they impact a vehicle or unit, but will only do enough damage to kill that exact unit, but will not damage an offroad for example. All of the grenades when fired from a rifle seem to act normally.