The game would simply have to check whether the switch is on or off to see which option to show. What occurs to me is that the game runs out of memory, or the resource to process this information.
This is the script of that event and as a result you have the different possible routes.
So you have triforce (The three girls) +Laura.
black & Red (Tia and Sarah) +Laura.
Caramel & Chocolate (Camila and Tia)+Laura.
Strawberry & Toffie (Sarah and Camila) +Laura.
Chocolate (only Tia) +Laura.
strawberry (only Sarah) +Laura.
Caramel (only Camila) +Laura.
And if none of the switches is activated, then the scene only plays with Laura, so I think the problem is that the engine is not able to do this operation in time and that's why the next content is not activated.
And yes, I was hungry when I did that scene, hence the names.