It seems when a character does a large quantity item transfer between the Warbank and inventory bags it causes an issue with logging out on that character. After logout or exit, the game stalls and the character remains persistent in the game world, but is unable to do anything or take any action.
At this point all I can do is exit the game, but the character remains on as if they disconnected and need to wait for the character to time out before I can use the warbank again as this counts as the character is still logged into the game.