Incomming calls no longer ring the user

[unmo]

3CX V.18.0 with call groups: Incoming telephones no longer ring the user / client, neither in the direct number nor in the call group. It's ringing if it's put over to him.
User have Cisco SPA504G and OS app iPhone.

 

[ChrisC_3CX]

Can you first provide a bit more info on your setup: https://www.3cx.com/community/threads/information-to-provide-when-requesting-help.67558/

Also, When you say its ringing when it's put over to him, do you mean a call transfer? If yes, can you check if internal extension-to-extension calls to that specific extension work? If they do please try ringing the Ring Group extension number from another internal extension, does that work?

If yes, it might have something to do with the DID matching, what happens to the external calls to the DID numbers associated with this extension? Do they just ring(caller side), does the call drop, do they get routed somewhere else in the PBX?