David R - Thanks for replying.
But it's up to the Avast team to fix this problem. The Avast plug-in for Firefox has a dramatically detrimental effect on
online.wsj.com
and almost as bad on
www.nytimes.com.
I tested my Firefox add-ons one by one, and the problem was NOT caused by NoScript or AdBlock. The Mozilla folks recommended I turn off the Avast plug-in and advised it would NOT disable the virus protection. Voila! Problem fixed.
And, per comments above, others have noted the same issue.
Also, I did not find a settings screen like the one you show in your post above. In one of my settings screens, two similar items were already off.
Down to you and the Avast team to check and fix.
Happy New Year.