Why did my watch stop answering my phone?

Hi , my watch isn’t answering or allowing me to make calls suddenly. I swiped up from the bottom of the watch and the antenna icon is not green. I have powered on and off both phone and watch, paired and unpaired. I have gone to watch app on phone and under cellular it has under the i “Apple Watch is active.” On the iPhone 11 I have cellular data and roaming on. Both operating systems are current. Should it show under Calls on Other Devices? I called AppleCare and was told it is my phone plan. My phone works with cellular, Bluetooth and WiFi no problem. I recently traveled and tried turning airplane mode off and on. Any suggestions? Thanks!! 🤞🏻