DNS address detected

With Avast Secureline VPN turned on, my IP address is changed but my DNS Address and location are correctly detected. I am using https://ipleak.net/ to check if it is working.

What’s the deal? There don’t seem to be any options or a help file in the app or any instructions on their web page.

Also, if I buy a license is there a limit on the number of devices I can use it on, or is it per device?

With a subscription you can install it on as many devices as you like as long as they have the same OS (e.g. Windows, Android)
You can however use it at only one device at a time.

https://forum.avast.com/index.php?board=80.0