Was wondering why players wouldn’t show up under my favorites after hitting the Favorite button. So I checked the network tab in Chrome DevTools and it appears that the Favorite HTTP request returns code 400 due to being a bad request. Maybe you’ve changed your api parameters so that they no longer match?
Hi @DeliciousCake,
Thank you for your report. I tried to reproduce the issue but everything works fine for me. Does it happen in all profiles on the website? Have you tried to reproduce it in other browsers or on other devices?
Hm, just tried on my work PC (also in Chrome) and it seems to work fine, perhaps I need to clear the cookies/cache.
On a side note, do you guys have a publicly available API for fetching player ranks, been trying to make Twitch command that displays a players rank in chat? 
Unfortunately, we are not allowed to share access to Rocket League APIs. You should request it directly from the game developers.