Hi! We aren't seeing any indication that your account is muted. Perhaps the issue is simply some other user interface difficulty? Possible issues that come to mind would be a hidden chat window, accidentally ignoring yourself through the friend's list, or perhaps not knowing you need to press enter once to bring up the window and press enter a second time to begin typing.
1- Are you seeing a chat window? 2- When you open your friends list and review the names of ignored players, is your own name on the list?
Any additional information you could give us could help identify the root of the problem. Thanks!