ranged mob issues

i made a bow which places lava blocks while flying. this works perfectly.

in the other mod i made, i made an item that shoots wither skulls that make giant explosions and made a boss use this  in its ranged attacks, which worked perfectly. 

so i made a boss shoot this lava boe

however, my mob simply refuses to shoot anything. i know because if it did, lava would be placed in the air

basically, ranged attack mob refuses to shoot.