1 - set to draw the linetrace, so you can see if really goes though the target.
1.1 - Does the line goes through the ball?
1.2 - What are the settings of your linetrace? (the collision settings of the ball i show in the last post only works if the trace channel of the linetrace is set to visilibity)
2 - is your ball BP only a sphere static mesh?
2.1 - Is this sphere from the default content?
2.2 - Does it have collision?
2.3 - Try setting the sphere collision to Block All.