No inbound call

I’ve installed FreePBX 17 on Proxmox, but I keep having issues with my trunk. It shows as registered and everything appears to be connected correctly, but no INVITEs are coming through. I’ve tried everything with no success.

I also installed IssabelPBX, which allows me to receive calls — however, if I enable “NAT = Yes” in the GUI, it behaves just like FreePBX.

What could be causing this? The only error I see in FreePBX is the following:
[2025-10-30 07:43:27] ERROR[1579] res_pjsip.c: Unable to retrieve PJSIP transport ‘0.0.0.0-udp’

Endpoint: infostrada_PJSIP Not in use 0 of inf
OutAuth: infostrada_PJSIP/390882xxxxxx
Aor: infostrada_PJSIP 0
Contact: infostrada_PJSIP/sip:[email protected] fedca1c9c2 Avail 59.319
Identify: infostrada_PJSIP/infostrada_PJSIP
Match: 151.6.0.0/16
Match: 127.0.0.1/32
Match: 151.6.115.166/32
Match: 151.6.51.198/32
Match: 151.6.73.252/32

infostrada_PJSIP/sip:sip.infostrada.it:5060 infostrada_PJSIP Registered (exp. 3s)