Very big issue of this addon is that it often doesn't automatically connect to NordVPN proxy after browser restart but icon indicates it is connected. The workaround is to enable kill-switch in firefox by setting proxy to localhost in firefox settings and then - to disable/enable addon in addons window every time the browser can't connect to the internet after restart. That way we don't accidentally use the browser without NordVPN proxy. Except for this inconvenience it is quite a good addon and the proxy servers are very fast. I'm enjoying using it. And I hope the issues (the one I described and some other minor described by others) will be fixed soon.