I have version 2023 (1001). Now here's something really weird. I closed out that song (without saving any changes), and opened another. Both are Christmas MGU files I've had for a long time. On the second song, the lead sheet displayed a single clef first time. Then, I went back to the FIRST song, and displayed the lead sheet again, and it displayed a single clef as well !! In options, single clef was checked but greyed out, and auto clefs was checked (something I had tried repeatedly before when it didn't work). Now I'm really confused. Don't know what was wrong, and don't know what fixed it. Just to be sure, I tried a third MGU, and it properly displayed a single clef as well. Go figure.