Unable to call to one extension

[Jonek]

We have a strange problem in our company. Two employees can use their phones as usual - receive calls, make outgoing calls to external numbers, and call extensions in the company. They just can't call each other. When they call the extension there is silence. No matter which employee calls, there is always silence. Other people can call them normally and they can call other employees without any problems - they are the only ones who have this problem among themselves.. The phones are updated. Previously, there was no such problem. Unfortunately, I did not find any advice on the internet that would work

3CX Version: Professional Annual 16.0.9
Desk phone: Yealink SIP-T46S
Provisioning Method: Local

 

[ChrisC_3CX]

Could you first provide more information as mentioned here: https://www.3cx.com/community/threads/information-to-provide-when-requesting-help.67558/

Also, as a quick test, go into the Management Console, edit both affected extensions and enable "PBX delivers audio" under the Options tab.