Hello, David. 

In the Coalition chat, you can communicate with your coalition mates. The main purpose of the Coalition Arena chat is to inform players what floor was cleared in a Coalition Arena event. It may help you to coordinate your coalition's efforts during the Arena event even more efficiently. 

Could you please clarify what kind of issue you are experiencing at the moment? 

Please provide me with screenshots, if possible.

Hello Davide!

The best way to discover the functionality of each chat is by trying it :) 

In my coalition, we are communicating with each other in coalition chat, but if we need to jump to Union Chat one of our leaders can put a message to do so. But I think each team can work on communication according to their own gameplay. We have a lot of communication possibilities!