cdm1550 uhf

I have a couple CDM1550 LS+ in UHF and have programmed them with GMRS frequencies. Channels 1-22 It receives without any issue on the channels. When I try and transmit I can get a brief (very very brief) transmission out before I get a tone back from the radio and all further transmissions...

I bid on a cdm 1550 on eBay and have won it. I didn't do alot of research on the specific model #. They gave me the freq it covered and I understand not all the 1550's are 160 channel. Anyone have insight into this model # AAM25SHF9AA5AN