Think it may be time to check inside the 9xl and see what's going on.

I've read about this before and if yours has a two piece rotor, one piece of the rotor may have come free on the staft and rotated with respect to the other. They are set on the shaft with opposing magnetic polarity and if free on the shaft (mine look like they are only glued onto the shaft) it will rotate. Motor runs sour or not at all then.