I've used GTM numerous times to fire LD-JSON business schema via a custom-html tag with Tag Manager. This time however, I'm running into issues.
The tags fire in the debug/preview mode of GTM, but when I publish it they are not found on the live site. Tag assistant shows no issues with the installation; I should add the custom HTML doesn't appear on the debug/preview, but the tag does fire (per the debugger).
The site in question uses WP-engine, but I've been told that's not likely the issue. If anyone can point me in a direction that would be great.
I posted on the product forums for google: https://productforums.google.com/forum/?utm_medium=email&utm_source=footer#!msg/tag-manager/RfxZcqbWrSg/wAWzn98TCwAJ
The issue here was GTM was using the 'document.write' feature for the custom HTML container (which housed the LD-JSON Schema). Removing that feature populated the site where Google could read the schema.
Props to Simo for being a 'sweet dude' for pointing this out.