Please help! We have a multi tenant 3cx server installed in a data centre. We have several Cisco SPA504G phones at various sites. All is well except for an issue with making calls after a transfer has taken place. The Cisco phones crash with the message "Answering" on the display when an extension, which has had a call transferred to it and the transferred call has finished, tries to make a call out. Like this: 1. Phone 101 receives a call. 2. Phone 101 presses "xfer" then dials 102 3. 102 picks up call and 101 presses "xfer" again to transfer the call 4. Call is transferred successfully 5. Once call is finished 102 puts the phone down. 6. The next time you to try make a call from 102 the phone freezes with the message "answering" on the screen, you can wait 1 minute , 5 minutes or 5 hours, it still won't let you dial out… unless (see 7) 7. If you do not dial out from 102 after the transferred call has finished but instead receive another inbound (which has not been transferred) you can continue to call out without any issue. NBs: We have tried latest and recommend firmware The issue can be repeated with 2 phones on the same LAN and on different LANS It can be repeated with PBX delivers audio ticked or un-ticked for each/both extensions It can be repeated with and without STUN Cisco to soft phone doesn't not show the issue. 3CX and Cisco support are doing a great job of blaming each other. Any ideas would be greatly received.