Mine did the same thing after the dealer installed my z1 kit. I think the tech adjusted the gates. The gates were adjusted all the way to the left causing the shifter to get stuck out of going into 5th. The tech did a 10 min adjustment and fixed the issue.

Same thing happened on my buddy's 2007 350z after a csc replacement.
It seems the gate has shifted and going into 5th & 6th requires some finesse.
Make them fix it.

What morons, they know it's wrong but don't want to work on it again so they convince you that black is white and off is on.....I have no respect/trust for stealerships, if I never have a car worked on at one again, it'll be too soon.

No, I'm not bitter, and I've never been ripped off by service....CAUSE I DON'T USE STEALERSHIPS....unless it's warranty and I guess I'd have no choice if it were a 1200.00 CSC replacement.
I feel for you Shawa. I think it's a metal plate that guides the stick shift that has to be adjusted. 'cause the gears didn't move in the tranny, just the position of the stick moving the gears together was changed by the shift plate being out of alignment.

The Flywheel is a dual mass, so no resurfacing, it has to be replaced, shitty deal.

OP, as for the change in shift pattern, mine was like that, I had them readjust it and back to normal, unfortunately I've had my CSC and MCS done a few times now. They have forgotten to adjust my reverse look out and shift gate both...
If you go HD clutch, get the HD CSC, the stock one wont last long with a HD clutch.