Lightning Trap Returning Projectiles only hit once

When you combine Lightning Trap with Returning Projectiles Support, only 1 returning projectile will deal damage. Tested on multiple mobs and bosses with big hitboxes etc..
Is this intentional as nothing on the gem(s) state that this is the case?

Returning projectiles only hit multiple if they have an AoE blast radius. The projectile itself does not shotgun, what gets you extra damage is the blast radius.