Not necessarily Linux related, but as people with Linux might be more likely to have a real firewall in place I will post this right here. I had to open up a bug report until a dev pointed out the actual changes that occurred.
Many useful firewalls might block port 5222 with a jabber or other google chat id code. It also goes to what appears to be a different server cluster entirely and not TQ.
If the chat window(s) are completely missing, and there is absolutely nothing useful in the logs then chat issues might be a firewall blocking such traffic. Once one identifies that this new port and IP combination are related to the game it is easy to fix.
CCP made this as a helper today: https://support.eveonline.com/hc/en-us/articles/360000592489
If you happen to be running an adaptive system like SNORT, the sigid: 2100230 would need to be suppressed.