Leonard: There is a Santa Claus but not at Onstar which is busy stealing the toys from good girls and boys. What started as a large upgrade to the Onstar and MyChevy app has taken a turn to a very dark place where software should not go. Without any notification functions on the apps and in some cases all functions have gone. Since there wasn't any notification one must assume this was a massive failure in software development. So far this has not led to a long line of unhappy elves streaming from the Onstar workshop but one can only hope for the best.
Meanwhile check your Onstar account in a browser and see if you are active. Some 2017s had three years and some had much less. Some of us have Basic plans and are being punished. For example I have Basic on one car and when I refresh the app nothing of value shows and nothing changes. Why would software have a refresh that does nothing?