Skyrim "Summon Arniel Gane" casting technique?

So I just got the spell to Summon the shade of Arniel Gane. However, it seems very difficult to cast correctly. It always seems, that out of the heat of battle, I can get it to work if I aim very carefully at a flat surface and look slightly towards the ground. But in the heat of battle I can never get a successful cast! It takes several tries to get him to summon where I point him. The spell looks like it works but I don't see the blue vortex or him anywhere. It seems to be related to how flat the surface is, i.e. I can only get it to work on really flat surfaces.

Any hints here?

EDIT:

After some testing it appears he DOES summon, but seemingly really far away and unrelated to where I was pointing. I was aiming at the ground slightly in front of me, and cast the spell. After searching around, he was trying to run to me from the right, but got stuck behind some rocks. Does anyone else have this issue?

When using summon arniel's shade i found it was better to summon him before a battle starts as it does not require any magika points or any of the likings also if you are having trouble summoning him up close try putting your cursor a few feet away from your character.