Accessed None error from a set variable node

I’m receiving repeating error reports of a null/none reference error while playing my game. The message logs direct me to the Set Inertia node shown below:


This is a detail of the blueprint:


During execution, the function will be called twice in a frame and the errors only report on the second call. I’ve added several IsValid checkers but all of them return true and I am most certain that the target is not null.

What seems to be the issue?