I use the cable on my ham and GMRS radios. Both models of radio with have o-ring like seals around the two mini-phone jacks seals that need to be compressed, so that could be a contributor. I presume these are for some measure of moisture protection when using headset and speaker accessories outdoors. Perhaps that little o-ring is a contributor.
Update: I managed to get mine to work... Had to push real hard to get it to make connection in the jacks. Not sure whether the radio's jacks are the issue or the PC interface cable plugs are the issue...
Sent from my iPad using Tapatalk