Duplicate content confusion

I just added an iframe to the domain https://sarahsembroidery.co.uk/products-workwear-hats/

Brilliant everything works. However I had a page already named ‘workwear hats’ located at https://sarahsembroidery.co.uk/workwear-hats/ and now this page is looking the same as the iframed page.

Why has the wokwear-hats non iframed page been replaced? Where has the content gone, it still shows in the ACP but not live on the site.