It could be a chat preview generator. Users DM links to some internal project pages in an chat tool and the tool fetches the page in the background in an attempt to render a preview.
In this case these appeared to be all MitM'ed pages from a security device since the key wasn't in the url and it contained userids for a specific user.
> * That somehow had the page content from a user
> * Would render and execute all scripts on that page as if it was that user