When a wire enters and leaves at different heights, it's a visual cue that the VI is wired correctly.
When a wire enters and leaves at the _same_ height, perhaps only the input is wired - you can't tell.
(There are two kinds of LabVIEW programmer: those who have been "bitten" by this bug, and those who will be.)
I'd argue these problems can happen anywhere, even when the inputs and output aren't aligned. And VI Analyzer is the tool to look for wires hiding behind objects. Wire cleanup and BD cleanup would also fix it if you don't mind that it may also change other parts of the wire or diagram.
This would solve the lack of visual cues better in my (biased) opinion:
Re-opening because LabVIEW NXG has been discontinued.