My Garmin inReach Mini will send text messages but does not include the location (coordinates) and it should. I’ve tried to reinstall the app with no luck.
Including coordinates as text in the SMS is optional. Log into explore.garmin.com, go to the Account "tab", and look at the SMS Message Configuration section in the lower right corner of the page. If you want the coordinates to be included in the SMS sent to the recipient's phone, make sure that the box is checked for "Include my latitude and longitude as text in the message".
There are no additional steps required to save the change. Also, this is handled entirely by the Garmin servers, so there is no need to sync the Mini.