Unable to use cellular apple watch with Jio

Hi team, I purchased Apple Watch 10 Cellular yesterday. However, since the setup ‘ addition of mobile service in the apple watch whenever I leave my iPhone at home, the calls are being returned to my watch! I checked the mobile service jt shows ‘No Connection’. I contacted jio they told to restart the watch & nothing much! What is the point of using this cellular version then if I am unable to utilise its full potential?