When I hold the button for 2 sec, the friendly lady says: "Onstar Ready". After that, she doesn't understand it when I say "Onstar". After a few words that she doesn't understand, she will list the available options. And "Bluetooth", "Onstar" or "Pair" isn't one of them.
Is this perhaps resolvable with a bit of re-progamming?
After pushing the button for 2 seconds and it saying Onstar ready, try saying bluetooth instead of Onstar. This almost sounds like the way my wifes 2010 Equinox is, you don't have to say Onstar.