ReplayPlayerController spawns without pawn

I just created a new PlayerController in BP and set it up to be used as ReplayPlayerController in my Gamemode, which works as expected. However upon spawn, the ReplayPlayer has no pawn(GetControlledPawn with IsValid returns false). I expected it to just use the SpectatorPawn. But it seems things are a bit different? Has anybody some more details?(as i could not find more details on this case in the docs. Or i missed them)