Found out that problem was because of Kaspersky Internet Security. Updating it to 2021 version fixed it. Topic can be closed.

That was very good work. Well Done. Please flag your last post as Solved Problem as this can help others with similar problems.

I have exactly the same problem, with the difference that I do not have any third-party antivirus, only windows defender, the one that comes included with windows 10, I already suspected some restriction, my defendants were windows defender or the firewall.

I still can't solve it, any ideas?

jhonatan1natanohj Please go to the top of any support.mozilla.org web page and use the Get Community Support link: https://support.mozilla.org/en-US/questions/new

Select the product for what the problem is (Firefox or whatever). Now select the category for the problem. At the bottom is Other.

Describe the problem in brief (one line). Then press <enter>. The website will display any prior posts that might help you. If nothing on the list can help, at the bottom press the button; ’’'None Of These Solve My Problem.

Now enter all the relative information on the problem. At the bottom of this, you can Add Images.

Under this is Troubleshooting Information. Please press the Share Data button. This will let us look at your system details. No Personal Information Is Collected.

According to my experience in forums, I do not know if the most appropriate thing is to open another topic since it would use the same title here already open, that is, we would have duplicate topics, that is why I limited myself to continue the thread instead of creating a new one.

here the image

I can't find the Share data button