Hi,

The people who answer questions here, for the most part, are other users volunteering their time (like me), not Mozilla employees or developers. If you want to leave feedback for developers, you can go to the Firefox Help menu and select Share ideas and feedback…. Alternatively, you can use this link. Your feedback gets collected by a team of people who read it and gather data about the most common issues.

You can also file a bug report or feature request. See File a bug report or feature request for Mozilla products for details.

but on the site by your link in the guideline has written: "No bug reports or support requests

Let’s get those to the proper places right away so they can be quickly resolved. If you have any how-to questions or are looking for help with technical or performance related issues, visit Support site. To report a bug, go to our Bugzilla site. ."

Yes, it would be good to report it on https://bugzilla.mozilla.org .