Unconnected nodes disable IA_Jump when removed

In UE 5.5.4, I have this group of nodes in my BP_ThirdPersonCharacter which were connected to an Enhanced Input Action for possessing another Character Blueprint.

If I unlink the IA and the nodes without removing anything from the blueprint, the controller still behaves as expected.

However, even though these nodes are no longer connected to anything, if I remove any one of them from my parent blueprint, any child of BP_ThirdPersonCharacter won’t recognise the IA_Jump input, which is completely unrelated to these nodes. The jump event is unmodified, and if I link a Print String to the end of the Jump action, it’s triggered in the parent blueprint, but not in its children.