That would be the work of your adblocker or A/V doing the blocking.

No it wouldn't be the result of my ad blocker or A/V. It is the result of Firefox censoring my content. I changed nothing since yesterday. Yesterday the comments were showing just fine. Today, they show up for a second and then disappear. Don't try to scam me with your phony reply.

well, there was no firefox update today or yesterday either. please take a look into your addons as they might receive automatic filter-list updates...

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See also: What happened to Tracking Protection?

cageiger said

No it wouldn't be the result of my ad blocker or A/V. It is the result of Firefox censoring my content.

Firefox does not censor any comments on Fox News - if your comments are "censored" it would be by Fox News :

Please see :

https://help.foxnews.com/hc/en-us/articles/233195088-My-comments-aren-t-showing-up-

and :

https://help.foxnews.com/hc/en-us/articles/233195048-What-is-the-Fox-News-Commenting-Policy-

If the above doesn't apply to your situation, and even though this only just started happening : If you use extensions that can block (wanted) content, like Adblock Plus, NoScript, Flash Block, Ghostery, would you please disable it/them and see if that will make a difference  ?