This from Mystery Box:
HDMI Note
Your HDMI cables need to support HDMI 2.0 (18Gbps) or higher for 50p or 60p capture. Many inexpensive HDMI cables are not capable of achieving the listed standard speed, so be sure to test any cables you plan on using with the GH5S and the Ninja Inferno to ensure they support 4K 60P / 4K 50P 10bit 4:2:2 transmission. If the cable doesn’t support it, you’ll notice the Ninja Inferno cutting out and flickering during capture, and segmenting the ProRes clips as if you had started and stopped the camera each time.
We brought in multiple brands of HDMI cables, and found that the Rocketfish cables gave us the best results.