Walkie Talkie

We have the Apple Watch Series 3. My son can talk to me with Walkie talkie but I can’t him. I’m under friends on his Walkie talkie but he is still under invite. I have done everything that was suggested and nothing worked. Can anyone help me. He got my invite and accepted it but on my he is still under invite and I can’t talk to him. But he can me. Please help. I have run out of options.