Since downloading X-Plane 11.35, frame rates have really dropped. Only fly single-engine aircraft at various small, challenging airports. I use an " iMac Retina 5K (2017), 3.8 GHz Intel Core I5, Memory 16GB 2400 MHz DDR4, Radeon Pro 580 8GB". Scaled back the sliders, but still have issue with 15 to 20 second screen freezes. Recommendations on settings or other various fixes would be greatly appreciated.