I keep getting a 403 error every time I try to access the Sainsburys supermarket website when the secure VPN is turned on in Norton 360.
https://www.sainsburys.co.uk/
A 403 error is an issue with the web site you are trying to view is not granting you permission to see the content. Many web sites do not allow access from known VPN IP addresses. They do this for copyright, legal, and political reasons. There is nothing a VPN provider can or should do to circumvent these legal protections.