Sorry if this has already been answered in a general sense somewhere else but I didn't find anything.
I have a simple set of nodes that splits a list of 2D points into individual data points and passes each one through it's own Smooth with Inertia node. Then recombines each data point into a 2D Point list the same length as the one that came in.
Feeding it unit test data in the same composition it works fine, and I'm using it in another much larger composition. But as soon as I make it a sub-composition and feed the unit test data into the sub-comp node it outputs a list of null data (same number of 2D Point elements but all (0, 0) in value).
The sub composition used in the above test rig: useful design.smoothListWithInertia.vuo