If I delete the ThirdPersonCharacter, it will be spawned in the location specified by PlayerStart Actor. If not deleted, the PlayerStart Actor will not work, no matter where it locates. This is wired. Do you know why?
I saw the 3) in your answer, and go to check Auto Posses Player In ThirdPersonCharacter. It was originally set to Disabled. I changed it to player0 > compile > changed it back to Disable > compile. Finally it worked! The DefaultPawn was spawned after hitting Play button.
Thank you so much for the answer!
Auto Posses Player is originally set to Disabled but takes effects like it is set to player0. I think this is a bug.
I had no idea there was a world override for gamemode, that is amazing to know! I had no idea the new third person template in UE5 defaults to overriding the gamemode. This was super helpful, thank you.