I just got both sandra's and vampire's cgs however in both of them out of nowhere the screens turns black leaving just the characters talking, is there supposed to me a animation on said screens?
Yes, that might be animated scenes. I assume you're on android? Not all phones seem to be able to handle the system I use for animations. I have no alternative at the moment, but I'll try to fix it at some point.
Can you still advance the events until the screen comes back?