Intra-site topic links to the same site don’t include the category or site name:
same site, topic: About the Feature category
same site, category: Feature - Discourse Meta
different site, topic: Category definition for Gaming - gaming - Discourse Demo
different site, category: gaming - Discourse Demo
vs. the same on Try:
(as to how you can change that, I’m not sure where that is, but that’s why it’s different)