Every evening between, approximately, 11pm and 12am eastern time, the chat does not accept login attempts. Sometimes this only lasts for 15 minutes, sometimes it's as long as an hour or so. The people who are already in chat are unaffected, just new people cannot join the chat for a while.
If that's when you're usually trying to log in, yeah, that'd cause a problem for you.
If you are experiencing a problem outside of that time period, it's likely an issue on your end as the chat has been up and working as expected.