Blank slide throws off scoring in Quizmaker 360!

Incredibly frustrated here! I added a blank (splash) slide at the beginning of an assessment to provide instructions, client branding, and passing score expectation copy. Cool. Great.

I added 20 questions, set passing score to 90%.

(Remember, technically there are 21 slides in QM).

When I take it (either in preview mode or published) and get all of the questions correct, my score comes to 95%! Probably because QM is somehow calculating in that extra slide.

What gives? I can't go in and exclude that blank slide from calculations because there are no editable settings for it (I get dashes in Question View for both Attempts and Points). The client asked for everything to be embedded in a single .quiz file, so I can't build out in Presenter or Storyline (and I shouldn't have to). 

I tried padding with extra points on one question (which is unacceptable to the client), but then Passing Points somehow changes to 95.

Can anyone please help? I'm stumped and flummoxed.