Charge measurements was done on both ETMs.
It is early enough to discuss the new tendencies, nevertheless it seems like ETMY change the sign of charging after changing the bias sign on ETMY (see 20387) while ETMX charging is the same (as well as the bias sign).
Now (since Aug,10) both ETMX and ETMY Biases are -9.5V, 
Plots are in attachment.