Its both brains. I’ve moved them around with no change. A few months ago I isolated the brains in that acclimation box and after a week or two it opened up. 20 minutes back in the tank and it closed up again. But I have never seen anyone messing with either of them. And the clowns used to host that one in front so it was used to the slight irritation. I’ve had that one for 6 years.
I bet you have a critter that moves back and forth just to claim it’s hosts. I hope you find what is doing this.