Unparsable structured data > Duplicate unique property

[mjukandco]

Hello everyone!

I need some help on how to fix this error. 

Recently there were errors in our site - raised by google search console - Duplicate unique property. I've identified that it comes from two urls:

https://mjukandco.com/collections/frontpage/products/champagne-pillowcase

https://mjukandco.com/collections/frontpage/products/crisp-white-pillowcase

And the field is @id. 

<script type="application/ld+json">
{
"@context": "http://schema.org/",
"@type": "Product",
"@id": "https:\/\/mjukandco.com\/products\/champagne-pillowcase",
"@id": "https:\/\/mjukandco.com\/products\/champagne-pillowcase#product",
"name": "100% Mulberry Silk Pillowcase - Champagne (22 momme)",
"url": "https:\/\/mjukandco.com\/products\/champagne-pillowcase","image": [
"https:\/\/cdn.shopify.com\/s\/files\/1\/0463\/5174\/5192\/products\/DSC07135-edited-small_1024x.jpg?v=1609605551"
],

...

Where and how should I edit this? I am using the debut theme. Also, what could have caused this? Funny how it only appears on these two urls when there's nothing special we did on these pages.

eg. There is https://mjukandco.com/collections/silk-pillowcase/products/champagne-pillowcase (they are the same product but the one with error was .../collections/frontpage/... and this one seems fine.)

On the day the error was raised(last Friday), the latest thing we did was to add a slideshow section to the site.

On a sidenote (This may be totally unrelated but I'm just listing it down to explain what I did today in case it helps):

Today, while I was trying to debug this I looked at developer tools and saw an error regarding the free shipping bar app we had(https://apps.shopify.com/free-shipping-bar). The free shipping bar was technically still there, but if you looked at the site it was not showing (covered by the slideshow). Hence I deleted the free shipping bar app and the error in developer tools went away. However, the error 'Unparsable structured data' is still there. 

Any help/explanation will be appreciated. Thank you!

[mjukandco]

I found the code in product.liquid file. Still not sure why it got changed and an additional "@id" was added.