US. I've heard it's slow to respond in Canada too from what people mention in the forums.
be willing to bet it is an undersized data center for the # of users and not the wireless network.
OnStar has 3 major call/data centers in North America, 2 in the US and 1 in Canada. with over 2000 servers at each location to handle the data requests, Their subscriber operators take in up to 100,000 calls per month and over 180,000 data transactions per week, and as of Q3 2018 over 3 million subscribers.
Hyundai Bluelink on the other hand has one call center for the US in Fountain Valley, and one for Canada in Ontario, and has yet to reach 1 million subscribers even offering it for free for 3 years. Bluelink and the call center is Hyundai owned and operated, debuted in 2012, and only operates in the US, Canada (limited) and Korean markets. and until 2014 used the Sprint network (yuck), but the data services are provided by a third party called Covisint Corp, who also supports, Land Rover/Jag, Mitshubishi, and Diamler.
OnStar has been around since 1996, and is a separate entity from GM, operating in 8 major markets (US, Canada, China, Mexico, Europe, BRazil, Argentina, Australia and New Zealand).
There is a significant difference in the size, operation, and technology between the two providers, Bluelink is still learning to walk.