We have a duplex that wont group together. We can make either car the master and it will take calls but it never sends calls to the slave car. We have checked all parameters and even compared them with another duplex group that we maintain. We didn't find anything out of the ordinary. Any suggestions on where to go next? We have even reloaded software. We're at a loss and are out of ideas. We don't get much help not being from TKE.