Yaesu-FT-991-group AM Transmit Audio

Yaesu-FT-991-group AM Transmit Audio

I purchased a new FT-991 late December 2015. Everything seemed OK with the radio until I tried AM. I wanted to participate in a local 6 meter AM net. The audio is distorted to the point where no one can understand me. I tried setting the power to 5 watts into a dummy load, lowering mic gain, turning off min-EQ, all with no success. I also noted downward modulation only. And yes I did a factory reset.

I checked with 3 other people who recently purchased the 991 and they all sound horrible just like mine. I am afraid this radio design is broken on AM. Good thing I kept the boxes. Anyone else seeing (hearing) this problem?