FlexPendant and .NET App Communication Issue on Real Controller

We have successfully established communication between the FlexPendant app and a .NET Windows application over the local network (192.168.x.x) by binding an SSL certificate generated using mkcert to the IP in the local machine. However, when deploying the same setup to the actual ABB OmniCore controller, the communication fails. We need assistance in identifying the root cause and resolving the SSL-related communication issue on the real controller.