Custom Layout shortcode in product description doesn’t work

Hi there!

I’ve been trying to insert one page into my product descriptions as shortcode across all my products, rather than having the same information copy+pasted into each, saving time for when that info changes it’s only one place I need to update it, not 20+.

I’ve used Insert Theme Shortcode > Layout Elements > Custom Layout, and while it displays correctly when I preview a product (Custom Layout_Preview), once it’s published and on the live product, it throws all this other code ahead of it and removes all formatting (Custom Layout_Published).

The page being inserted via the shortcode is ALB, and is just a text box

How may I get it to display as it does in the preview, on the live published product page please?

I really appreciate any help you can give. Many thanks! :)