Could you describe the circumstances in a little more detail. For example are you typing a single word with the intention of accessing a local server or performing a search, and instead Firefox puts www before and com after to turn it into a domain guess? Or are you typing a domain and after you hit enter Firefox adds www to the beginning? Is it on all sites or particular sites?

You can set some related fixup prefs to false on the about:config page if you want to prevent Firefox from adding the www. prefix.

• https://support.mozilla.org/kb/search-web-address-bar
• https://support.mozilla.org/kb/awesome-bar-search-firefox-bookmarks-history-tabs

simply trying to be able to access sites that don't use www.

and as for about:config, been there done that no go

If you try this link, does Firefox add www?

https://jeffersonscher.com/res/jstest.php

What is the scenario where it adds www?