Originally Posted by
FlyDeltaJets87
Perhaps OP rebooked himself into a Y fare and then received the upgrade from having the Y fare. That's my guess of what happened. Accurate? I dunno.
This is almost certainly what happened - an IROPs Y booking. I've had my same flight show up on the app with FC availability to rebook before, but I've only gotten error messages when trying to do so, which IMO is correct (if the glitch is going to let me see the flight at all, that is). I haven't had IROPs since the new app rolled out to Android, though, so I don't know the behavior now. Good ol' Delta IT.