@TeamYouTube I'm not getting any videos for "up next" I've tried clearing my browser (Firefox) cache then tried using chrome which also didn't work. I'm on PC and it's the only device that I'm having the problem.
Appreciate the report – we'd recommend sending a feedback report directly from YouTube, here's how: https://yt.be/help/feedback . That helps us identify and fix widespread issues. Make sure you're logged into the account experiencing the issue when you send it in!