storyline 360 Review Quiz displays incorrect on correct answers

Note of caution...I found the issue to be intermittent, even with clicking speed consistent throughout test runs (in as much as a human is capable of it). Hence there may be other factors in play. Also, the marking discrepancies varied from one run to another; my best guess is that it may be related to question and answer shuffle settings.

It's a slippery one. It will take many hours of testing across multiple Storyline quiz instances before I'm convinced that any future solution has fully addressed the problem.