Some browser configurations may interfere with the functionality of Bitdefender VPN’s Ad blocker and Anti-tracker features. Specifically, when a browser uses a custom DNS server or advanced blocking technologies, it may prevent Bitdefender from properly blocking ads or trackers. When this happens, Bitdefender will not filter browser traffic but will continue to filter all remaining device traffic.
If you wish to adjust your browser settings to allow Bitdefender VPN to work uninterrupted, here’s what you need to do:
For Google Chrome 
1. Open the Menu in the top right corner and choose Settings.
2. Select Privacy and Security in the left menu, then choose Security.
3. Scroll down to the Advanced section and then disable “Use Secure DNS”.
For Mozilla Firefox 
1. Open the Menu in the top right corner and choose Settings.
2. Select Privacy & Security in the left menu.
3. Scroll all the way down to “Enable DNS over HTTPS” and then select Off.
For Microsoft Edge
1. Type edge://settings/privacy in the address bar and scroll down to the Security area.
2. Disable the option “Use secure DNS to specify how to lookup the network address for websites”.