Never use a VPN when playing at bitcoin books. I see a lot of complaints. The biggest reason for confiscation of funds at bitcoin books is using a VPN to play at a banned country.
If a site is centralized, it is better not to use VPN at all, some gambling sites disable users not to use VPN but some allow users to us VPN, I have not used VPN on any gambling site before as I prefer to use the IP address of data provider as my country support gambling. I have heard may complaints too about the use of VPN but I see no reason why the betting sites do not disable the VPN access to all users, rather than enable it but just to make sure such user lose in some ways if his way on the betting site is not totally legit in terms of the site ToS.
Are you sure about the url sportsbet.one? The website is unknown and doesn't belong to a existing casino.
The one we know is
https://sportbet.io which is a legit site, no one should follow a site having a similar name to Sportbet. I cheked the site domain and I saw nothing as it is not yet registered, if the site is truly existing, people should just avoid it to avoid scam.