So, the relevant code is:
<input type="checkbox" name="choose1" id="front" value="Front" />
<label for="front">Front-end Projects</label>
<input type="checkbox" name="choose2" id="back" value="Back" />
<label for="back">Back-end Projects</label>
I would recommend you stop using Bootstrap. It interferes with the lessons in raw HTML and css the curriculum has been teaching up to that point. You have gone div-crazy trying to get the layout and styling right (a common problem in Bootstrap).
I tidied up your HTML using CodePen’s menu in the HTML pane, and I noticed that the fieldset tag was at the same level of indentation as the
<form> tag at the top, which implies that the fieldset can’t be a child of the form (can’t be inside it), it has to be a sibling (next to it).
Get rid of the extraneous
</div> tag, and all 17 tests pass.