Description:

You have been logged out.

Description:

You have been disconnected.

First solution(Legion only):

Change your Portal to "legion.logon.firestorm-servers.com", To do this just go to your game folder > WTF > Config.wtf then change your first line to SET Portal "legion.logon.firestorm-servers.com" as shown in the screen below.

Configuration

Second solution:

Check if your computer meets the minimum system requirements for the game

Update your drivers and operating system to resolve compatibility issues.

Reset your interface to make sure your files and add-ons are not corrupted.

Reset your network devices to make sure your router is not overwhelmed with data.

If you're using a wireless connection, optimize your Internet connection to avoid connection problems.

Try to close all background applications to resolve software conflicts.