To add, I've went back to a save for M'ap Tann Pelen and made sure I did Tapeworm first as I noticed the first Tapeworm dialog should talk about Alt (didn't in mine) who is not engaged till M'ap Tann Pelen. After doing those in order, I was able to break through to Nocturne etc. It also unlocked an entirely new scene for Gimme Danger that didn't happen on my first playthrough