NS no longer removes tracking cookies from Firefox

NS used to find and remove on average 30 tracking cookies/day, when doing a Quick Scan.

After recently updating Firefox to version 50.1.0, NS no longer detects any tracking cookies.

 

I tried turning the Detect Tracking Cookies option OFF and then back ON in NS settings, but that did not fix the problem.

I tried turning the Browser Protection option OFF and then back ON in NS settings, but again, no luck.

A Google search shows that various people have run into this problem over the years, after updating either their browser, or Norton. However, I could not find any solution.

A few weeks ago I contacted Symantec customer support about this. The agent said he will submit the issue to a more senior level of support and they will contact me within the next few days. (Needless to say, I never heard back from them since.)

 

Any ideas/suggestions on how can I get NS to remove tracking cookies again?