What is suddenly blocking me from accessing this site?
It loads the site and I can see my balance, but the site is now putting up a message that I cannot access sportsbet.io from my jurisdiction...
Also, how is it telling my jurisdiction? From my IP?
What can I do to get around this?
Like everybody said, use a VPN. There are a few that are free like cyberghost and other ones, I recommend this one since this is the one I use. The free version is fine. Then the best thing you do is just withdraw everything and move to another sportsbook. There is no more point in playing somewhere that banned your country. There are a lot of alternatives anyway.