Support Specialist 3 Task Bug

For the Support Specialist 3 challenge, it only counts direct impacts with the launcher. 

After testing for 2 days I confirmed myself that it does. After aiming at the ground and shooting, allowing enemies to walk into the fire did not count towards any damage for the challenge. I stayed at 128 damage and got 10 kills which feels like should have been more than that. The first 128 damage came from direct impacting enemies with the incendiary launcher. Which I did manage to kill 8 enemies with. 

So from what I can understand the Incendiary launcher for some reason only counts damage that comes from the projectile itself. It should also count the fire damage that results from the projectile. Otherwise the challenge would be quite tedious to do since direct impacting with the projectile does little initial damage.