3CX v18 Makecall Relay to softphone client

[wamot]

Hi,

We are building an integration between 3CX and our own API to create a make call.
The service is deployed to linux box. We can transfer the call to the client(softphone) only once after that we cannot start a call again after we make a call.
We need to restart the service to makecall again.

How do we release the client(softphone) without restarting the service?
Any sample C#.netcore codes to do that?

Below code causing the problem and cannot initiate another call.
PhoneSystem.Root.MakeCall(registrarRecord, toNumberCall);

Thanks,