Yes, here is the long-winded expanation from our developer
What happened is that when we were developing embedment I noticed the grey margins and wanted them to be white so changed the background property to ‘Transparent’ which on Chrome turned them white
However Goggle changed Chrome so it was black instead of white in the latest release, when I reverted the above BackgroundType property to Default the grey margins returned but the report was white as it says above.
So reading the documentation again I realised my mistake was to take the Chrome background default for a div as white and not force it to be white regardless of the browser default.
So now I’ve restored the Transparent as the documentation above says and forced the div to be a white background, see below.
This now means it’s all working as before with white margins and white background when in full screen .