Hi Jim, have you found what's wrong?
I'm using SW2017 SP5 too and I have issues as well. Mine is a very minor one!
It's a cropped a broken-out section - crop outline not shown. The hatch came automatically from material properties. The hatch is protruding out of section in the top left corner and there is a line missing in the bottom right.
It's not a problem at all for me on this as it can be barely noticed in the drawing, but it's an abnormal behaviour that can not be controlled.
Have you figured this issue out yet? I'm experiencing the same thing in SW2017 SP5. I can't seem to get around it, and it is very frustrating.