Hello,
The blueprint and code for this device is setup to use the collision volume. In the case of a spline that collision is just along the spline it’s self and not the internal area or bounds. I brought it up to the engineer who implemented feature as the spline is a unique edge case, and to see if they wanted to handle that object differently or add a way to hand internal bounds.
A work around would be to convert your spline shape into a unique object or objects and custom shaped collision that would fill that internal space.
Not sure if you seen this before but could be helpful.
