Incoming call issues

Hi all,

I’m having some problems with our PBX.
Asterix is 11.14.1
PBX ver 2.11.0.43

We are based in UK and the problem we are experiencing is that some calls are coming through and some won’t.
I have tested it using two different mobile operators Vodafone and EE.
Vodafone success rate is 100%
EE success rate is 30% - call are being dropped as Call Failed

Now once I’m connected via Vodafone the audio is two way, when I’m connected via EE (eventually) the audio is only ONE way!

Same symptoms as to EE calls have been reported on some landlines, but Vodafone goes through with audio every time.

Any idea?
Also:
GW_TrunkOB2 109.224.232.216 Yes Yes 5060 OK (24 ms)
TEST 109.224.232.218 Yes Yes 5060 OK (24 ms)