Well I know why it wasn't working with the direct connection, someone set up something for a similar reason. We have a estos UCServer that handles our IP phones. I can see the incoming traffic from VAPI, and there I have the error

08.08.2025 16:37:02:200;1;6176;ASN1ERR;local: 10.10.10.1:13852, remote: 44.229.228.186:13719 unknown encoding