Call is routed but 180 ringing does not arrive so no ringing heard

[asarril]

I have a weird set up.

I have public SIP trunk to make calls, that SIP trunk is connected to firewall Fortigate.
Firewall redirects anything that comes for the IP of the trunk on my side to the PROSBC
PROSBC has a SIP trunk to AVAYA CM

When an Avaya extension makes a call to an external number this call goes through this SIP trunk to the PROSBC
PROSBC routes the call to the SIP trunk of the provider and this works fine.

The problem is that the extension does not hear the ringing when calling.

Checking the call trace i see that the public sends the 180 Ringing but is does not go through PROSBC.
I also see that the public sends the 180


<= 180 Ringing

Send PRACK request

and I see a lot of the late, send PRACK request.
I remember before having to change the AVAYA SESM for PROSBC this was an issue, the prack packet that does not pass.

Ive been told:
You can configure the PRACK in the SIP  SIP Stack configuration and modify the value of Provisional Response Type parameter.

The only Provisional Response Type parameter I found was in Header section and it was SUPPORTED

What can I do to let the PRACK pass?