official-stockfish/fishtest#697 (comment)

https://opensource.apple.com/source/Chess/Chess-110.0.6/Documentation/PGN-Standard.txt

"Export format requires each tag pair to appear left justified on a line by itself; a single empty line
follows the last tag pair."

I have not verified whether it's 100% a cutechess problem.