I have two sites with two separate deployments and have purchased the OVPN licence to allow users to take their desk phones home during the virus emergency.
On one site it's working brilliantly but on the other site it doesn't work at all. I have exactly the same configs, firewall and even have one handset working on the questionable site but any more than that no joy.
They connect to the VPN server and I see them in the PBX backend but I only hear their audio on a test call, they can't hear mine.
Under Sip Settings / Network
Try adding the 10.8.0.0/24 subnet to the Local Networks