I get this too, although I’ve not tried to sort it out yet. I did notice the other day that my rear calliper isn’t quite central on the disc.Anyone else suffering from badly resonating XT brakes on the E+1? Screeches and resonates so bad you have to let go the brake and reapply.
I've changed the pads, realigned the caliper and axle, use brake cleaner on the discs (they never got contaminated), check the bolts and the disc is not warped
Help, not sure what else I can do!