Throwing a trident through lava make it on fire but not make mobs on fire

So I am not really sure what is the bug so I will explain what is happening with the trident...

So I took a trident and throwed it, and it moved through the lava, and by that it was on fire. But the problem was that as it touches an entity, the entity is not on fire, like arrows through lava that makes mobs on fire.