PBX A and PBX B, both are in the same DataCenter, dedicated LAN and WAN IPs, each PBX has a SIP Trunk (same carrier) no Trunks between the PBXs. Both PBXs user Asterisk 16.6.2
When any extension of PBX A calls the main number of PBX B, there’s RTP both ways just fine, they can dial extensions, speak with users, no DTMF issues etc. and vice versa.
The only time we have an issue, is when a user of PBX A reaches a Voicemail on PBX B, PBX B stops sending RTP to the carrier after the beep which obviously results in the call greeting disconnected after 30 seconds.
Is there any setting that we might have missed?
Again, to confirm, when anyone is calling the PBX from their cellphone and leaves a voicemail there’s no issues then.