Basically it seems that the imessage app on iOS basically can&#x27;t be bothered to check every number every time a group message is sent. So once it has found you were a imessage number you are forever an imessage number within that group.<p>The only way to break it, as best i know as an outsider, is for everyone else in that group that are imessage users to delete the group and start over.<p>Likely it is another one of Apple&#x27;s &quot;usability optimizations&quot;, like how they would broadcast every last SSID you had been in contact with to try to speed up reconnects.