Some respondents report not seeing slider on some questions

adstr_bepp
The only reason I can think of here is Theme issue if you're using something custom made or any Custom CSS which is probably overlapping with the browser compatibility.
Hope it helps!

https://community.qualtrics.com/XMcommunity/discussion/comment/51134#Comment_51134Hey Deepak , I appreciate the suggestion. I took a look into that. I have a blank theme with some custom CSS but can't really see what would be causing the issue. To me, it seems like my custom CSS doesn't interfere with anything so it's looking more and more like a pure browser compatibility issue (i.e. the browser has it's own default CSS that could cause the slider not being shown). That's just what I think - coming from someone with little experience in HTML and CSS. Below is my custom CSS as well as a screenshot of the web inspection of the slider. Let me know if that helps narrow things down further.

I also just learned that the respondents who could not see the slider also could not see the timer which makes things more puzzling to me.

#frame {
   width: 700px;
   margin: auto;
padding-bottom: 35px;
   outline: 1px solid grey;
   text-align: center;
font-size: 1.1em;
color: #000000;
   background-color: white;
   position: relative;
 }
 html {
   background-color: #ccc;
 }

/* NOTE: On Temp6 its height=10px. Don't delete from Temp6 */
#topMargin { 
  height: 1px;
}

 .smTab {
   padding-left: 30px;
 }
 .lgTab {
   padding-left: 60px;
 }

html .Skin #Logo {
  filter: none;
  height: 57px;
width: 770px;
    background: url(https://upload.wikimedia.org/wikipedia/en/e/e9/Penn_Wharton.svg) left center no-repeat;
  border: none;
display: block;
}

.Skin #LogoContainer {
display: block;
padding: 0px;
margin: 0px;
height: 57px; 
}

.Skin .QuestionText {
  background: #FFF;
}

.Skin {
font-size: 18px;
background-color: #fff;
height: auto;
}

.SL {
height: 510px
}

adstr_bepp ,
Add a metainfo question to your survey. That will help you determine if the issue is specific to certain browsers or devices.
Why is there styling for #frame? That's unusual.

adstr_bepp
Couple of questions and yes this could be a browser compatibility issue which you will have to monitor via either UserAgent Embedded data or MetaInfo question.

1. Why do you have skin element you can do those things with Qualtrics inherent capabilities


2. Why do you have frame element is it for mobile browser compatibility or different screen sizes, if yes you are doing it incorrectly.