Polycom IP331 Incoming rings but cannot answer call

[Alldayrr]

All,
I'm currently using V15.5 and setup my Polycom IP331 phone to register to my 3CX PBX. I'm able to call out fine and receive incoming calls but I'm not able to answer/pickup the call that's incoming. Everything else works fine except the answer button and speaker button is disabled on incoming calls. Do you know what the issue is?

 

[lneblett]

When one of these calls comes in, what is the CID showing? Is it normal or something odd.

Have you done the firewall test and did it pass? If not,then please do the test.

 

[Alldayrr]

It's showing the number correct number. Incoming looks fine. The firewall test passed. I used the pbxexpress install. I hear the ring and see the incoming calls come in but it won't let me pickup the call. It just continues to ring. I'm able to reject the call from the phone but i just can't answer. I'll pickup the handset or press the speaker button, or click answer, but it still keeps ringing. Does this have to do with a setting in 3CX? Keep in mind, I also provisioned a softphone so both ring at the same time.

 

[leejor]

You might need to employ Wireshark to see if the set is sending a message back to 3CX when answered. If it is, then, for some reason, it's not reaching the PBX. If you confirm it isn't, then you have to figure out why? Faulty set, or misconfiguration.

Is this only happening on one set?
Did the set work previously? Is it new or used?
Has the set been "factory reset" then re-provisioned?
Does this continue to happen if the set is moved to a location, on the network, that eliminates any switches (any devices) between it and the PBX?