You get the same error as previously posted? I cannot reproduce this issue after pulling down your project and making the change.
Check that the object created by NewObject’s outer is not the transient package (and further, that the outer’s outer and up the chain as much as may be needed, is not the transient package).
There may be some corruption due to more clean-up of the Blueprint instances already placed (if any), so you could try a new level (and perhaps a new Blueprint) to see if the issue lingers. With the code provided, the object should no longer be a part of the transient package.