Problems machine polishing on curved body panels

I've only used my PC about a half a dozen times (so I'm no professional) but I encountered something that I've never dealt with before. Well actually I have but not as frequent as this. When trying to polish my daughters 2015 Hyundai Accent I noticed in many of the concave areas of the hood, doors and bumpers, the pad would stop spinning. I tried different angles to get the pad to spin freely but when I succeeded it was not full pad contact and I had to lift off some which in the end yielded sub par defect removal results.

I was using 5.5" pads with a speed of 6 and while they were obviously too large for these contours, what else could I do except buy smaller pads for these sections? Or is there a technique that I am unaware of that I could apply to these areas?

My other concern was that the machine may not be performing at 100%. It was way to easy to stop the pad in these areas. I do realize it is a safety feature of the machine which is great but it really didn't take much effort. In fact in speeds slower than 5, I am unable to apply ANY pressure other than the weight of the machine because if I do, the pad stops spinning.

Do these machines need tune ups occasionally?