In my game you can summon them, but I get the 3x3 thing as well. It works if you select an enemy as the center tile; and it spawns on the same tile as the target.

The game also sometimes "forgets" you've summoned an Air Elemental, and lets you summon a 2ed! It correctly remembers that the other summons have already been....summoned.

i just tried it again, and either my elemental is invisible or it's just not wanting to work.

I confirm that I'm having similar issues, but my air elemental remains stationary/immobile for the entire combat.

ok, so after having shut the game off and coming back to it, my Air elemental now summons some of the time.  there are times when he won't show up because someone fell on his square (annoying to waste 40 mana for a no show), and other times where he shows up even though someone is on his square.