Slow wifi when using Norton VPN - ORBI RBR 750 Model

I have a RBR 750 Router and when I use Norton VPN I am getting slow speeds or poor connectivity. I called the pro-support 2 times and am getting fustrated after hours of waiting and being transferred up to 3 times and being disconnected without being call back, even though they have my call back number. Has anyone experienced this issue with slow speed and VPN usage, and are there solutions?