Conditional elements not appearing on some pages

I’ve got a weird one… conditional functionality has stopped working on some pages… but not on others, and I can’t see what difference(s) between the pages concerned could cause this. At first I thought it was the slider on the Home Page, but problem exists on pages without the slider too.

I’ve tried displaying the various forms concerned on blank test pages with nothing else on them, and they all work fine, so it’s some kind of conflict I assume, but I can’t nail it.

These are very simple forms – email address (only), and an ‘opt-in’ checkbox appears as soon as you start typing in the email field. For those seeing the site URL: this no longer works on (for example) the Home or Author pages, but works fine on the ‘CEO Executive Coach’ page. (I stress, although these are different forms, they are practically identical, and I’ve tried swapping them – it’s definitely about what page they’re on).

Looking at the console, I can see a JSON Uncaught SyntaxError (on page load), only on the pages where it isn’t working. So something is scrambling JSON…

That’s about as far as my technical/scripting knowledge can take me! If anyone knows how I might identify what the difference is between the working and non-working pages, or how to find out what’s conflicting… ideally without having to disable plugins one by one (there are rather a lot on this site) I’d be very grateful. Many thanks.

P.S. Looking at the logs, I strongly suspect this stopped working in late October, and I’ve only just noticed… in case that helps nail what might be causing it! (Every entry since then is ‘opted out’, which is the default).

• This topic was modified 4 years, 1 month ago by wwwolf. Reason: EDITED to change URL to a test page, demonstrating problem with EBD+CF7-CF

The page I need help with: [log in to see the link]