You are welcome
For finding the reason of overflow (it is what cause gap on the site) I usually open the live/published site in the browser “code inspect” mode, make it shown in mobile view and then step by step go to add overflow: hidden to every big sections CSS settings. When one of the section react on this (gap disappears) I remove overflow: hidden from the section CSS and do the same with elements (rows, divs, etc.) inside the section. When one of the elements react - I am going deeper 
Logic behind the magic.
Cheers,
Anna