Why is the submit button not working?

So this is yet another frustrating, inexplicable issue I'm having in Articulate. I'm trying to design a multiple-dropdowns question for an assessment. In preview mode, the interaction is submitted just fine and advances to the next question in the assessment section of my course. 

When I publish it to the LMS, for whatever reason, the submit button doesn't submit the interaction and advance. It...just doesn't work. 

Can someone please help with this?