I’m not sure how reliable this is but Janet ditched Together Again due to technical issues
https://tucson.com/entertainment/music/janet-jackson-ditched-together-again-after-glasto-technical-issues/article_9527558a-9b1a-5330-bcb4-c3e6093d0592.html
“It's a shame because we had technical issues at the start so I couldn't play my last song, 'Together Again'!"
However, Janet said it didn't put a dampener on her first Glasto experience, and she admitted she was overwhelmed by how big the world famous festival is.
She said: "It's so big, I heard stories about it every year but had no idea and then we saw all the tents."