I sent the 90 cross off to a friend with his layout. it looks like the pin arrangement is the cause. If there is a pin on the center rail of the cross the rail is dead between there and the switch at the bottom.
I usually have to do surgery on the bottom of across to isolate one line from the other. The four center rails of the cross are connected together. I suppose you could move the pins to the N-S sides of the cross and remove them from the switches to isolate N-S from E-W. But then the engine would momentarily be on the other power district when a roller was on a cross rail and the back roller on the second power district. Not good.
I haven't tried to open a cross like this. Only FasTrack.