The standard shaft is 1/2 inch longer - I'd anticipate hitting too high. Trying to swing for the fences? LIkely you'll shorten your swing arc if you have too much tension. Relax and let the club be magic?

Paul,
Sounds like first night nerves...
I had the same issue with an 818 hybrid, where the fitting went very well and we had fine tuned for flight, distance, grip size and everything that could be dialled in.
When I picked it up, unlike other Titleist hybrids which I took to straight away, I couldn't knock it off the mat....
Thought I'd made an expensive mistake....
Couple of further sessions and all is sweetness and light. We are a matched pair. Money well spent.

Take a deep breath and go back to the practise bay.
JT

I too experienced the same thing when I switched. My fitting was done in doors in a controlled type of environment. Of course actually outdoors on the course can't be compared. It did not take me long to realize the problem was between my ears and not the club. Good Luck!