I have the same problem with AudioCodes 402. Can make outside calls but can not receive the calls form outside. Here is my log
13:11:52.234 AuthMgr:

nAuthFailure [CM101000] Registration request from sip:
[email protected] failed. Reason: Credentials don't match, check that authorization-ID and password match the ones in extension settings
13:11:52.234 AuthMgr::requestCredential [CM001005] Message SipReq: INVITE
[email protected]:5060 tid=-899-21965c-1aa199b5 cseq=INVITE
[email protected]:5060 / 2 from(wire) failed authentication!
13:11:52.234 AuthMgr::requestCredential [CM001003] Authentication ID for Ln:10005@Audio Codes 402 BRI doesn't match provided: vs 10005
13:11:35.359 AuthMgr:

nAuthFailure [CM101000] Registration request from sip:
[email protected] failed. Reason: Credentials don't match, check that authorization-ID and password match the ones in extension settings
13:11:35.359 AuthMgr::requestCredential [CM001005] Message SipReq: INVITE
[email protected]:5060 tid=-888-215476-32a53393 cseq=INVITE
[email protected]:5060 / 2 from(wire) failed authentication!
13:11:35.359 AuthMgr::requestCredential [CM001003] Authentication ID for Ln:10005@Audio Codes 402 BRI doesn't match provided: vs 10005
13:10:00.125 ServRegs:

nAdd [CM113002] Registered: Ln:10005@Audio Codes 402 BRI
I have given correct passwords and user ids. No mistake with this. I guess there are some other parameters I have configured in 3cx. I have to say that I did:
Caller-ID is in 'user' part of (one of following):
'From' field
Called-Number (for inbound calls) is in:
'To.user' field
waiting for your replys,
regards,