iWatch Walkie-Talkie

Recently purchased and activated 2 SE watches. Updated OS to 7.2. Both are WiFI+Cellular. Both have been number synced to their respective iPhones (on IOS 14.2). FaceTime is set up and working as specified on the phones. Cannot get walkie-talkie to find the contact of other to send it an invite (Contact is not available for walk-in-talkie error message). Get same message on either watch. One is brand new and one has been used for a month, so the whole unpair/re-pair seems silly. Any ideas to get it going?