Simon, I typed up from memory so sorry I misled you.
Your problem is exactly as i guessed in my first Reply.
You moved the Page background rounded Black Rectangle from origin.
It shows as:
The two negative values should be (0, 0).
You also should never work with the Page background unlocked, as you can move it in error.
In passing, your landing page is far too wordy, few will read; Google will flag the font size as too small. You have a fair few typos to correct. Purple prose on purple will flag up poorly in Google's Accessibility.
You could improve the site's download and performance by not using a Shadow on the Page background Rectangle.
Your biggest gain will be to tick Web Properties > Website > Other > Shapes as SVG. This alone gives a three time speed gain on loading the page. Useful if your other 16 pages are similar.
Acorn
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