Strange, I had what you describe the other day on an E. It was a split of 4% max but would change from no.1 high to no.2 high and back. I decreased power, switched LD share to TOT and let it stabilise and then back to Torque and it all went back to normal.
Told engineer and he just scratched his head, asked if it was normal on the following sectors, it was, and that was the end of that.
I'd love to know more.
Lunar