Background image views massive on iPad

Hi there, we are using theme No8, but have a problem with background images viewing massive when viewing on an ipad in horizontal mode, do you know about this? Can you help? For example:

https://runforthehillslondon.com/commissions/
Views fine online, but on a iPad (retina) views the background image massively so you can’t really see anything. I would show a screenshot but you won’t make anything out because we are zoomed in on a tiny portion of an enormous image and it;s just black.

the row is set up like a section, and Full height regular, static parallel.

Please help!