I think it’s a bug… I even tried the solutions they gave you and it still didn’t work. You might want to create another topic under Freecodecamp support.
The solution in the Guide was missing the original h1 element. So it appears, you were just using the same solution that was incorrect. I have now updated the solution in the Guide.
You can click Reset All Code to see what the original editor code starts off as and try to solve it again without looking at the solution.