For the past 4-5 days there seem to be twice as many english world chats as usual, it started around when the leaderboards went wonky and were showing 2 entries for every player. There doesn't seem to be a huge influx of new players so unless there really is an uptick in traffic the game is just spreading the chats too thin and that kinda kills them all.
For example, around now there would usually be 1 world chat, or one regular chat and a small overflow. Instead, there are three rooms that have all been dead for 40+ minutes: https://i.imgur.com/EVjZYNG.png
So... might be something to look into. Chat is quiet enough when it's not buggy.