I'm really confused at everyone elses confusion. THis is a simple concept . <tt> = Target of my Target /Target that this target is targeting. If you are trying to heal the target of your target... and your target is the tank..... the tank will have a monster targeted. You can not heal a monster therefore you will default to yourself. Working reliably and as intended.

<tt> Is more appropriately used for offensive abilities for example Energy Drain. Using <tt> for healing and supportive skills is just.. well silly. Your tank or party members are never going to have each other targeted unless by freak misclick and even in that case they would unlikely have the person you are actually trying to heal targeted... Stop using <tt> on cures... it's not intended for that... If you are trying to make a macro that heals your target use <mo>,<t>, <me> or <p1-8>.