Check whether you've got the correct window or executable name selected. Create a Scene named Game or whatever you want. In the Sources pane, click the "+" symbol and add the soruce you want. Here I have Window Capture selected. Double-click that for the settings. See the annotated screen caps below. I'm capturing a window here, but I tested with a full-screen recording earlier, which worked fine:
Ok, I think I got it. So, every time I want to change the game I have to double click window capture and change the setting to the game. Yes, I tried this and it works. Thank you. This is the first time I have really played around with OBS, so still learning. I've been streaming on XBOne and PS4 so far, so this is new to me. Again, thank you.