GOautodial Open Source Omni-channel Contact Center Suite

I've got a goautodial 4 setup in some rack space and some agents using it remotely (behind NAT). It is setup with an SSL cert, the agents can login and make calls on ratio dial no issues but randomly agents get no audio on their 2nd drop in call on an outbound campaign and then no audio from then on, every call from the 2nd call just produces no audio, both parties cant hear each other (the agent and the lead that was called and dropped into the agent).

What we discovered was if the agent logs out and back in again using the same agent number it just keeps happening but if the agent logs out and logs in with another user agent number the problem goes away (but then pops up somewhere else to another agent later on, it seems to be random).

We've tried both chrome and FF, no plugins like adblock or ublock origin, nothing, just bare bones browser installs. We tried clearing cookies etc and logging back in as the same user agent but the only way to get that agent back calling is to have them log out and relog in again with a different agent number.

The logging out and logging in as another user agent number kinda rules out PC or mic issues.

We're using WebRTC for the agents not sip.

Interestingly if someone goes and blind monitors that agent the blind monitor person can hear the call but not the agent it dropped into.

The install was done from the latest ISO and updated using github to the latest version.

On occasion too the hung up button goes missing, it is not selectable and the agent gets stuck looking at the lead details of the call, they cant hangup or do anything other than log out basically.

Campaign is on ratio dial but once this issue of no audio pops up you can try and manually dial a number out of the agent interface and you get the same no audio doing that as well.

Anyone got any idea what is going on here?