Fork with Frostbolt Doesn't work

I am sometimes just testing what works with what.
I noticed you can put fork support gem into Frostbolt but than the frost doesn't fork.

I dont know if this is intended or not but shouldn't the frostbolt itself than split into 2 projectiles? since i can put it in there.

Nevermind, Noticed the '' if they do not pierce it '' discription on fork. forstbolt pierces in nature. but still weird you can put fork in it when it doesnt effect it

I think is because if you use Snakepit Pearl Ring Unique you make the Frostbelt Projectile not pierce thus allowing the Bolt to Chain and Fork, haven't gotten my hands on one of them yet but it seems that it would work that way.