Hiding question with js

Hello, 

I have a slideshow with 5 images that participants click through. After they have clicked through all 5 images, I want

1. the Next button to appear (hidden before)
2. a question to get hidden (which was visible as part of the instructions to the slideshow before)

I have the following code, that does 1. but not 2. Any thoughts on what I am doing wrong?

viewedSlides.add(slideIndex);
      if (viewedSlides.size === x.length) {
        Qualtrics.SurveyEngine.setEmbeddedData("allSlidesViewed", "true");
          jQuery("#NextButton").show();
          jQuery("#QID80").hide();
          
      }