I am a long-time user of Ivacy and have been using the Firwfox addon for many months now. I notice people complaining that it fails to do this or that. Not in my experience, but it is quite sensitive to being correctly set up. Also, it fails when the internet fails and it seems that ISP's don't like VPN, so they are running short-term interupts to the service, to try to force your VPN to turn off. That way they can see what you are doing. Be aware that HTTPS connections are encrypted from end to end anyway, so they can't read those even if a VPN turns off.

You may need to make provision for Ivacy to have a route through your firewall. The easy way to know if that might be your problem is to close the firewall and then see if Ivacy runs. I had to do that in Linux.

Customer service at Ivacy is superb IMHO.

Ivacy has apps for Windows, Apple and (Ibelieve) Android, but under Linux you have to create the VPN copnnections yourself and it won't work if you have any error in your settings. The instructions are quite clear, but they do have to be followed in detail.

I hope some might find this useful. I love Ivacy and I came to it AFTER trying other VPN services !