Randomize Cases (not questions)

Hello,

I created a course where learners are randomly served 1 of 3 CASES (each with their own set of 5 questions). I did this by putting the screen that takes learners to each case in the question bank, but kept the questions themselves out. Learners get to keep trying until they pass - they are taken back to the title screen to pass through the "randomizer".

 

The issue is: Randomizing works at the first attempt, but the second or third attempts assigns me with the same case each time. See attached.

 

Can anyone tell me why Storyline isn't randomizing at the second and third attempts?

OR

Is there another way to randomize cases that I haven't thought of?

Ref: Case #01543586

Any help is greatly appreciated!

Note1: The attachment was the file I used to test the randomizing. I've already fixed the formatting and results slide or any other glitches you may notice.

Note2: I left the menu so it's easy to go back to the title screen.