Since the previous maintenance, I've been getting random 90000 errors every single evening during peak hours for my server (JP group). I can get 90000 disconnected even when I stand in town and chat on FC.

It feels like the server is just randomly dropping people when it can't take it anymore. Perhaps the servers are tuned too tight. I play a tank so these past few days I've avoided going into dungeons at evenings, in the hope that it may improve.

During the day (off-peak) I can play for 10 hours straight without disconnecting. I'm on a dedicated fibre connection, too.