I don't know how to edit or delete my previous post. I wanted to correct it but I can't, so I'm sorry but below I am sending it again but corrected: Hello, I worked at the computer on the night of July 9-10. I turned on Firefox and it happened the same. I was able to check that Firefox has updated to version 78.0.2. Maybe it has something to do with something it contains, e.g. something related to security. Here is it description: https://www.mozilla.org/en-US/firefox/78.0.2/