I think I am having the same issue but only for the rear camera. Here are the steps:
1) launch the camera app. By default you will be on "photo" mode using the rear camera. You can then swipe left to go to "video" mode or swap right to go to "portrait" mode.
2) When I swipe right to go to "portrait" mode, the display freezes. The buttons are not working (shutter, settings, reverse camera, etc). The only thing I can do is swipe again left or right to go back to "photo" mode or "pano" mode.
Everything else is working for me except for that "portrait" mode when using rear camera.
I hope I explained it well.
Please disregard as I just noticed that this is not the correct forum for ROG Phone 2
