I've wired this exactly like the diagram. I'm going for a parallel connection so I've done.

Blue+Red to A+
Blue/White + Red/White to A-
Green+Black to B+
Green/White + Black/White to B-

But someone else told me that it should be as

Blue+Red to A-
Blue/White + Red/White to A+
Green+Black to B-
Green/White + Black/White to B+

I've tried that too and nothing. No improvement.

This is happening on all 3 axises. I cannot get the motors to rotate smoothly, they are rotating in jerks.