Calls dropping when using wired ear pods

During the last couple of weeks, my iphone XR has been dropping calls only when I'm using wired ear pods. I routinely have to call a person back six or seven times per brief call—embarrassing with clients! I have tried using different pairs of ear pods, calling from different residences (city and country), and moving to various rooms in the houses. These calls are all made using wifi. When I remove the ear pods, the phone works fine. I've tried restarting, upgrading to the latest software, and cleaning the jack. The routers are working fine since the calls drop only with the ear pods. Help! TIA