Auttaisikohan Ubuntu Pro? Mulla oli se U18.04:ssä ja mielestäni Firefox päivittyi melko tuoreeseen versioon.
"Ubuntu Pro is an extended security service that includes up to 10 years of security updates, and this applies to packages installed on Ubuntu, including Firefox. By default, modern Ubuntu versions use Firefox as a Snap package, which will be updated and secured through the Ubuntu Pro service. You can use the standard Ubuntu Pro security updates, or you can manually update Firefox through the browser's "About Firefox" menu for the latest version, as explained on Mozilla Support. "