you'll need a script command in addition to the event to solve this.
Because the event command to change battleback only changes it in the map property, to update it on the battlescreen you'll need to force the engine to update it after the picturesetting was changed.
and no, I don't know that command, I only remember reading about this.
I sweep the floor. My brother, "You didn't do a good job. There are dust bunnies everywhere." He sweeps the floor weeks later. "I just swept. Why are there dust bunnies everywhere?" Me," Guess you didn't do a good enough job."
Oh god, just watched HawkZombie's stream of my game and realised that *none* of the branching scenes work properly. One has no character graphic, one soft locks due to a passability issue, and one doesn't have its autorun set to the right trigger. I've got first prize in the bag, baby.