Assuming that TracerEffect is a blueprint with a projectile component, there is nothing wrong with it. Unreal doesn’t know automaticly, when something needs to be destroyed. I assume you use the projectile component, so here is a possible solution for your problem:
Video:
Basicly do, what I did in the video to your own projectile blueprint/Trace blueprint.
If you use a different kind of hit system, you just have to keep in mind that you have to destroy your traces, when they hit something (except line traces, but that’s a different thing) :).
A little advice though: Be careful with projectile actors and multiplayer. They are not network friendly on the get go :).