I can see from the triggers on your Try Again button that you have the Jump To Slide action happening before you have the reset counter variables actioned. Unfortunately, this causes Storyline to jump back without resetting the counter variables so this is why you can only select one or two before getting the 'You have made 5 choices" message.
Also, you have all three variables being reset on the 50 score layer. This should be repeated on all three results layers.
Move the Jump To trigger to be the last action the buttons have to perform.
But there are a lot of other issues going on that will impact the usability of this interaction such as some options deducting 20 points off the total instead of 10. Is that intended?
There are 4 'correct' options on the first slide and 3 on the next but the user is being asked to make 5 choices per slide (as the instructional text asks them to).
Currently, if the user gets all 7 options correct they still are presented with the "Unfortunately, you did not score great" message.
And at the risk of being hyper-critical, is there any need for the popups to appear when an option is hovered over? The popup content is the same as the option content, is it not? The user doesn't need any unnecessary information thrown at them.