This seems to be zone specific. Zuldazar has 3-4 second delay on any action, my latency is normal. Flip over to Orgrimmar and no lag, come back to Zul and lag comes back, fly to Nazmir and no lag, same with Vol’dun. The only thing that has resolved the problem is switching warmode ON and LFG. Since I missed mentioning this previously, this is specific to the realm Maelstrom; at least for me. Joining a group through Group Finder works, best paired with taking over that leaders realm before they leave group.