Unable to gain XP/wins on Trivia leaderboards, new personal best from yesterday lost

Yesterday I put in about 12 hours on Trivia, gaining around 1.2m xp on the leaderboards. I also achieved a new personal best score of 9300. Ever since this morning, I can no longer gain XP or wins on the Trivia leaderboards, and my personal best in my collection book has reverted to my previous personal best of 9150.