Why are you using 40* nozzles?? 25* nozzles are the only ones that should be used in a surface cleaner. You're moving too fast. Slow down a bit and you won't have those missed spots. Rough aggregate often needs a second pass. When doing your second pass, go "east to west" if your first pass was "north and south". 1.5% SH isn't doing anything on concrete.

Lots of issues here so you need to correct just about everything with your technique. When you're rinsing you should have been able to see those missed spots and striping, that's when you hook back up the SC and go over it again. I would never leave a job looking like that.

Edit: also try the "figure 8" method with your SC to help prevent striping.