https://mybluelink.ca/ is the OFFICIAL Hyundai website to connect to their cars.
It doesn't work in any device connected to my home wifi. But works just fine if I am connected to a VPN or in other networks like Shaw or on 4G (mobile).
I tried tracing on a Shaw network and it works just fine...
I am able to bring up that website without issue on my Telus connection using my wired Windows 10 desktop (Chrome), Windows 11 laptop (Edge, wi-fi), and on Firefox on my iPhone connected to my Telus home wifi. What message are you seeing when you try to access it from your wifi?