My first Flex radio. Loving it except - The 6400 doesn't transmit in either FM or NFM with either + or - offset. It does transmit in simplex FM & NFM modes and other modes (USB, CW). I tried cold boot several times (6400 OFF, PS OFF & disconnected for more than a minute, reconnect, PS ON, 6400 ON). same result. NO XMIT! Running SmartSDR 2.2.8.