i cannot get both iPhone cameras to work in OBS (mac). Only one at a time will work. I can switch between the iPhone 7, the mac's webcam & the display capture but the iPhone 5 is always a black screen. If i try the 5 on its own it works. Tried different resolutions & all usb ports, with and without hub. New to OBS, but I'm pretty techy. Anyone have ideas? (2011 macbook pro, El capitan 10.11.6, OBS 24.0.2, iPhone 7, iPhone 5.)