In GMATPrep software, do Practice Content-Review Questions duplicate any questions included in the two CAT tests or OG?
You shouldn't see overlap between GMATPrep and OG. Between the two tests, you won't see overlap either--UNLESS you repeat the two exams. This is a relatively common practice, to reset and retake the GMATPrep. The question bank in GMATPrep is relatively limited, so that risks seeing repeated questions.
Hope this helps!
