So i was editing my video normally when suddenly the preview had a weird white glow around the border. This happened before but usually I just restart the program. I was kinda lazy and didn't want to do it. Then I noticed that if I had any media (Text or image) on a timeline above the video then it would black out the video completely and only show the media (it will only show the topmost media. So for example if row 1 is the highest and row 3 is the lowest. If I have a text media in row 1, a image in row 2 and the video in 3. Then it will only show the text that is in row 1 and black out the image and video in rows 2 and 3)

I use keyboard shortcuts alot and I might have hit something on accident? How do I undo this and what is even the point of it?

Using Vegas pro 19 (Build 651)