Hub motor rubbing noise

I have a pretty new bafang hub motor (65 miles) on my ebike that is making a metal rubbing noise when I go past half throttle on the thumb throttle. Between zero and 50% is smooth, no noise but after 50% up to 100%, it makes a noise like metal rubbing. I checked the disc brake and looked at everything else and I don't see anything rubbing.
I have replaced the controller with a new one, same model and specs, and that is when the noise started. I took the controller off my wife's bike, which is the same as mine and it works fine with no rubbing, but when I put my new controller back on the noise is there again. It looks like the controller is the issue, but I don't know enough to know why it would work up to 50% perfectly but rubs after that.
I have been reading through other posts from people that had a noise like this but they don't seem to be having the same problem as me. I would be very happy to hear any help or suggestions from you guys. Thank you, Mick