Mis alligned Parallax images

Hello Guys n Gals

I’m developing a website for a local Fish n Chip Shop, using the new 2017 Theme. Whilst I like most of the Theme, I wanted the sidebar back on the front page and other pages and followed the instructions on this post:-

https://wordpress.org/support/topic/twenty-seventeen-how-to-get-sidebar-on-pages/#post-8532954

by swayam.tejwani

I’m sure I’ve followed all the steps and whilst it does show the sidebar on the front page, the first image shows ok and full width, but the images on the following sections, show in the page content area and not before the page. my site is -:

http://mobys.community-theatre.co.uk/

In addition, the parallax images display correctly when the page is loaded singularly.

Anybody have any ideas???
Many Thanks
Phillip