YateClient won't ring when called via IAX

[mistaken]

I'm using YateClient 6.1.0 with asterisk over IAX. Yate doesn't ring or detect an incoming call, although other clients such as Zoiper work fine. Outgoing calls using Yate work without a problem.

I'm not sure what is the problem, though my issue seems to be similar to the one reported on mantis quite a few years ago:
http://yate.null.ro/mantis/view.php?id=235

Here are some debug logs from the client. Can anyone tell me what's wrong? Is this an issue in my Asterisk setup or in Yate?

Code: [Select]

Yate 6.1.0 - 1
Registered account iax:mistaken@example.com
Returned true 'engine.command' delay=0.003973
  thread=0x7fc244000b20 'Engine Worker'
  data=(nil)
  retval='Message sniffer: on, timer: off
'
  param['line'] = 'sniffer on'
2018-08-07_22:06:05.367283 <WARN> IAXIEList::createFromFrame. Frame(6,1) with invalid IE [0x7fc228001950]
2018-08-07_22:06:05.367319 <iaxengine:INFO> Received frame [0x56052367cbb0]
-----
IAX (0x06) - NEW (0x00000001)
  Incoming from 10.0.0.1:4569 (Local address: 0.0.0.0:4569)
  Call (Local:Remote): 0:5047. Timestamp: 5. Retrans: false. Sequence numbers: Out: 0 In: 0
  VERSION: 0x0002
  CALLED_NUMBER: s
  CODEC_PREFS: EOJDV
  CALLING_NUMBER: 3339994321
  CALLINGPRES: 0x01 (allowed,user-provided-passed)
  CALLINGTON: 0x00 (unknown)
  CALLINGTNS: 0x0000
  CALLING_NAME: XXX YYY
  LANGUAGE: en
-----
2018-08-07_22:06:05.387306 <iaxengine:INFO> Sending frame [0x56052367cbb0]
-----
IAX (0x06) - ACK (0x00000004)
  Outgoing to 10.0.0.1:4569 (Local address: 0.0.0.0:4569)
  Call (Local:Remote): 5132:5047. Timestamp: 5. Retrans: false. Sequence numbers: Out: 0 In: 1
  No Information Element(s)
-----
2018-08-07_22:06:05.387369 <iaxengine:INFO> Sending frame [0x56052367cbb0]
-----
IAX (0x06) - INVAL (0x0000000a)
  Outgoing to 10.0.0.1:4569 (Local address: 0.0.0.0:4569)
  Call (Local:Remote): 0:5047. Timestamp: 5. Retrans: false. Sequence numbers: Out: 0 In: 0
  No Information Element(s)
-----
2018-08-07_22:06:05.387392 <WARN> IAXIEList::createFromFrame. Frame(6,1) with invalid IE [0x7fc228001950]
2018-08-07_22:06:13.651909 <iaxengine:INFO> Received frame [0x56052367cbb0]
-----
IAX (0x06) - HANGUP (0x00000005)
  Incoming from 10.0.0.1:4569 (Local address: 0.0.0.0:4569)
  Call (Local:Remote): 5132:5047. Timestamp: 8291. Retrans: false. Sequence numbers: Out: 1 In: 0
  CAUSECODE: 0x00
-----
2018-08-07_22:06:15.643868 <iaxengine:INFO> Received frame [0x56052367cbb0]
-----
IAX (0x06) - HANGUP (0x00000005)
  Incoming from 10.0.0.1:4569 (Local address: 0.0.0.0:4569)
  Call (Local:Remote): 5132:5047. Timestamp: 8291. Retrans: true. Sequence numbers: Out: 1 In: 0
  CAUSECODE: 0x00
-----
2018-08-07_22:06:15.643914 <iaxengine:INFO> Sending frame [0x56052367cbb0]
-----
IAX (0x06) - ACK (0x00000004)
  Outgoing to 10.0.0.1:4569 (Local address: 0.0.0.0:4569)
  Call (Local:Remote): 5132:5047. Timestamp: 8291. Retrans: false. Sequence numbers: Out: 0 In: 2
  No Information Element(s)
-----