For Future Travelers:
Scandanavian Airlines app (SAS) does not appear to work on GOS. Enabling GOS compatibility features & following other troubleshooting steps did not resolve the issue. I have not seen this particular app discussed elsewhere, so I will document here.
SAS flyers will have to check in at the airport, or online if possible. Print out your boarding pass at the check-in station before passing through security. Otherwise, no critical issues - you can connect to on-board WiFi and purchase through browser. You can fly SAS without the app, just marginally less convenient. As is life