M9 gimbal yaw not working

I recently discovered that my old M9 gimbal was not working and had a drift of 5-50 micro seconds. I ordered a new one thinking that maybe the sensor was going bad, but the new gimbal has the yaw completely unresponsive. Is this something that I maybe have to configure in the radio? I ordered another M9 a year ago and had the exact same problem. Ultimately, I’ve had 3 M9 gimbals all with some kind of yaw issue. Is this common? Thanks.