You are not alone in experiencing this bug. I’ve linked the competitive bugs megathread at the bottom of this post, which archives and documents almost every competitive bug. I put your thread under: Not Appearing On Leaderboards (Season 6). Please help in spreading the word about this megathread and other related threads regarding these issues.
Here’s a thread about your missing Top 500 leaderboard placement issue if you’d like to read more about other potential solutions: The Competitive Bugs Megathread - #318 by Azdyph-1127.