useContentfulLiveUpdates - RangeError: Maximum call stack size exceeded

You might miss passing sys.id property to the useContentfulLiveUpdate.

// `post` should contain `sys.id` property.
const updatedPost = useContentfulLiveUpdates(post);

It’s necessary that the provided information to the hook contains the sys.id for identification.
https://www.contentful.com/blog/elevate-your-contentful-and-next-js-workflow-with-live-preview/

useContentfulLiveUpdates may recursively search sys.id property in its object.