Hi Ryan,
Thanks for finding the forum and posting here.
I’m sure you have double-checked that the tournament slug is “test-tournament” and that the games are in the “test-tournament”. That being the case, this is usually a symptom that your site is running an other version of PHP. Please check your version of PHP against the WordPress Requirements. (You need 7.0.)
Let me know how that works out.
-Mark
BTW, I do NOT recommend using the same tournament title more than once (ever) AND that when you delete a tournament, you also empty the trash. Otherwise it’s slug still exists. WP will handle duplicate slugs in a way that makes sense, but it often causes confusion by admins (me included) because they don’t remember that trashed posts and their slugs still exist in the WP DB.