Has there been changes to the Prismic API - January 2024

Hi, i have a site thats been running fine over the last year. Some updates have been made a few weeks ago and again the site has been running fine. Today i've come to start local development and i'm getting the following error which is stopping the page rendering.

Server Error
Error: An invalid API response was returned

I've also noticed on the live site that certain data is getting CORS errors when fetching data which is done though content relationship field and other pages rendered using getServerSideProps are all showing 500 errors.

From looking at settings i've noticed the API endpoitnt contains cdn where as the url in my sm.json file doesnt.

Has there been changes?

We're tracking the issue here: