level does not complete

I've just bought the Undergames addon. Latest version as of a week or two ago. I've played at least two of the missions now as different characters where I won, the game realised I did (the interface disappeared etc), but no move-on/continue popped up, nor any winning speech. I'm left in limbo. The win doesn't register with the game itself so I have to play the level again and hope it works.
I think it's because I'm loading the game.
Obviously this makes the game uncompletable unless I manage a several hour playthrough in a single sitting with no mistakes.