Homepage Wont Display Featured Products

As you can see from the screenshot below, I have my home page set in the admin area to:

configuration/index listing/Show Special Products on Main Page = 1

All of the four test products I've added to the site so far are indeed special products. However, they simply won't show. Can anyone see from https://www.superfancy.co.uk what is going wrong?

I just reverted back to the classic green template to see if the featured products would display on the home page and they do. Therefore, whatever's causing this is one of the template override files? Would that be correct to assume?

Does anyone with more experience have any idea which file I should be looking at replacing?

https://www.superfancy.co.uk

If this was database related, then what field would be causing it?

If you do a view source you can see that your html is a mess on multiple <html and <head tags ... search for them without the closing bracket as you have additional info in them ...

I've actually found a culprit file:

/includes/modules/CUSTOM/specials_index.php

This was a modified file (which was working well until earlier today). It doesn’t work any more. It basically changed the way the products display the model number and so on when you’re in index list view. I’ve reinstated the original classic file. I have no idea what’s caused the file to stop working, but at least I know what file needs to be re-modified. Getting there (slowly but surely).

I know the pages on this site are messy and don't validate. I'm an amateur remember :)