Thanks for your reply Klara.
I have a colleague who have set up a survey123 with a scroll bar, so my problem is trying to find out why he managed to do it. As far as I know, he used the iFrame option in the layout builder to add in his survey. I have attached an image of the survey here with the scroll bar:
But basically, what you are saying that I should find another option for my survey, since a scroll bar is not ideal in the design, or supported in all browsers?