Free VPN is not working. browser.ipProtection.entitlementCache "subscribed" value is false

Hi there, I have recently started using Firefox but the free VPN is not working on my account. When I click it, it says it's on, but I can confirm it's not actually doing anything. I've looked into other posts on this topic and tried all the remedies I can find to no avail. During this research I found that in my about:config, the browser.ipProtection.entitlementCache data reveals what I think is a flag to say my account is not "subscribed" to the VPN. For the record, this is a shared home computer and the other person using it has their own Mozilla account and the VPN works perfectly on that account - so it's nothing to do with the installation; we're using the same software on the same PC on the same Windows account. Is there something more I can do to get the VPN working on my account? Thanks