Wrap pattern along cylinder

I've done this many times before, but SW2017 just fails on pretty much every feature of this part.

I've always had a hard time lining up the wrap pattern along the face of the part and coming out correctly. But now 2017 seems to have just given up...

This was cutting the slot in the proper place until I increased the instance count, now it's just being stupid.

Any clues?

Or better ways to do this?

Design Intent:

SolidworksParts And Features