Hopefully that was useful to someone and if you have any follow up questions around finding out if you have a problem feel free to reach out to me to discuss!

Also if you made it this far, please also enjoy this picture of my homemade graph

Typically if you have an issue related to this you will see pages in Google Search Console (GSC) either totally unknown to Google or crawled not indexed if the page was found elsewhere exclusively.

Whilst this is great for users don't miss out on having that content available to bots so you can try to showcase it earlier in a users search.

If you are trying to see if your website has an issue like this, look for pages that have pagination. This is most commonly where these issues crop up. But also be mindful of detail pages and product variants, interactable elements are commonplace where input from the user is wanted.

This mostly becomes a problem when a page relies on context or content from a previous page. Unless that information is passed, such as with a query string, it will be lost when fetching the page directly. If that page is only accessible via interaction on another page then it simply won't be found

In essence it means every page is individually fetched, like typing the URL directly into the address bar, effectively this means that any interaction that happens between pages wont happen for crawlers, for example in an infinite scroll when you reach the bottom and load the next set of results

Currently we are dealing with Google marking first party content as third party and slapping a client with a SA abuse penalty.
I am extremely frustrated