How to change possessed actor with debug play?

I was following a YouTube video series to learn Unreal Engine and at some point I may have misclicked or accidentally bumped a hotkey, because now whenever I hit the “Play” button instead of possessing the “ThirdPersonCharacter” and entering the world from that location, a copy of the ThirdPersonCharacter blueprint is spawned at the “NetworkPlayerStart” position and I end up controlling that copy (with the original ThirdPersonCharacter actor just sitting around idle at spawn)

I literally just picked up UE4 like one day ago, so I’m incredibly new and don’t understand anything. Small words and pretty pictures appreciated.