I have had this exact problem since 4.0 - My <mo> macro does not target the mouse over, or the , <2> (tank) and would go to the last line <me>.

This is incredibly stressful on huge pulls with my crappy physick/adlo shields - one miss can be very bad, but this is worse than a miss, is a whole GCD wasting time and mana healing myself.

My only fix has been to remove the "healspell" <me> line and to spam my skill (it doesnt cast at all on some clicks now, but doesn't heal me at least) - it feels very wonky and I see it as a serious issue to be honest.

NEVER had this happen pre-Storm Blood

It is not "twitching" on the the player list or anything like that - this is a real problem for me only since 4.0.

I appreciate the fact not everyone has had this happen, but your post has confirmed I am not going mad.

I thought it might be something to do with line of sight now - you cant see through certain things (like Garuda's rocks now) and is somehow interfering with ranged skills?