Ajax issue in wordpress

I am using this jarvis one page theme and in the portfolio/products section have these issues: see url: [login to view URL] - Full screen parallax slider shows partly in portfolio section behind items - items have some gap on right side, cannot fix it.. added less or more items, always gap and messed up - "load more posts' bar shows up in wrong place - when an item is clicked it loads on top of portfolio items, then any other items appears to load but then shows only the "X" and nav arrows but not the content itself. debug and find out if related to anything i added so i can change what i added so no need to modify files. If modify files put in child theme. Make sure works on all browsers and mobile too. i think someone with experience can fix this in an hour or less and for 30$