You have to choose the Section Link option and in the drop down select the section you want to link to… (currently you have chosen the link option instead)
Once i removed that Div block everything works perfectly… you have to drag your sections out of that block before you delete it… … but it Looks like you are using that div block to hold the large background image. use should use a fixed position image in your body section for that ( i believe) i’d have to play around with it to no for sure.
…and it looks to me that you have some styles in the contact section. ( the button, the text, etc) not sure what you keen.