Newton's Cradle Not Working

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Newton’s Cradle is not working as it should. The balls that get hit by the one ball move together, as a group.

Anyone has any idea why or how I can fix this? It’s probably a momentum conservation problem, but I don’t know what I could change to make this work.

sorry, this is not a solution, because the ue4 physics system can be kinda tricky and hard to debug from he outside.
You can have a look at this if you like:
https://forums.unrealengine.com/unreal-engine/marketplace/1519779-pendulum-physics-props