Extensions appears ON but after 20 sec they go OFF in polycom 601

HI. I am config the recent install pbxinaflash (freepbx)
I begin to add all the extensions in my polycom 601 after reboot polycom extensions appears just fine as loged in. but after 10-20 sec the extensions appears off (logedout) I havent put any trunk etc
why the extensions appears on but after 20 sec they go off ?
any idea

this is frustrating. please drive me in the right direction

PD. I have 6 extension in polycom 601 and I have a gateway portech with other extension
the only extension that remains on is in the gateway

thanks so much for any help