After finishing my first fight in the strongest ninja tournament, i automatically exited space time. This had no consequences for gameplay since i could re-enter for round 2 without any problems. But the space time chat stayed with me and replaced the normal group/world chat.
After the second round the same thing happened, and only by entering into space time again, all the way into the group sections and exiting did the normal chat re-appear again.
Its not gamebreaking, but its still a bug.