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.

UPDATE!

In the child blueprint, if I create a new node for the IA_Jump and link it to a random function or event (as if I were to overwrite the parent function in the child blueprint), the possessed character goes back to recognising the jump input, allowing me to delete the unused nodes from the parent blueprint.