No audio on Android 3CX app

[NaHoW]

Hello,

I am experiencing issues with incoming call on the Android app.
When I pick up the inbound call there is no audio.
The activity logs learns me this:

10/03/2019 6:48:46 PM - x-call-control DROP: call is not found: kB3KOlj8lf6y2pFOP9vKuA..;from-tag=ac1b9b41;to-tag=a660ec64

10/03/2019 6:48:46 PM - [CM503003]: Call(C:26): Call to <sip:[email protected]:0> has failed; Cause: 487 Request Terminated/INVITE from 127.0.0.1:5483

10/03/2019 6:48:46 PM - [CM503003]: Call(C:26): Call to <sip:[email protected]:0> has failed; Cause: 487 Request Terminated/INVITE from 213.118.xxx.xxx:3151

I have this issue when I use the phone on LTE but also when I use it on Wifi in a network that runs hardware VOIP phones without problems.
The PBX is hosted on OVH VPS. The firewall test returns everything green.

What is more remarkable is; when I try to forward the call to and external numbers (which currently I can't cause the trunk only supports 1 session) and then return to the call the audio is fixed.

Any hints here? I've checked most of the other threads and I see they all point to a firewall issue somewhere. However, the firewall test works, the VPS is on a static IP with no extra firewall. On the hardware side the hardware phones within the network run fine.

Any help is greatly appreciated.

Kind regards,

Simon

 

[leejor]

Is the issue only on one phone, or several? Has it been this way all along, or just start? You say you use it on Wifi, do you mean on the same network as the 3CX server, or a hotspot? Have you tried using with/without the tunnel?

 

[JohnS_3CX]

Please provide the exact versions of your PBX and your app