Course not advancing to next slide when learner clicks "Next"

Hello,

I am a bit stumped on something that I hope has a simple, obvious solution that I am missing.

I have a course with 60 slides. On slide 41, when the learner clicks next, the course jumps to slide 54 for no apparent reason. Here's the scope of my troubleshooting so far:

• Slides 42-53 exist, and are right in line between 41 and 54. I see no reason why the course should jump from 41 to 54.
• The trigger on slide 41 indicates to jump to the next slide, which should be 42 (not 54).
• When I change the trigger to jump to slide 42 (by naming slide 42, not just leaving it as "jump to next slide") the course still goes to slide 54.
• When I click slide 42 in the menu, the course goes right there. When I preview slides 42-53, they exist and work just fine. I simply cannot make slide 41 go to slide 42.
• I have deleted and recreated the trigger several times, as well as have tried deleting the next button and re-adding it to the slide. No amount of trigger changes will make slide 41 go to slide 42.

Help? Please and thank you?!