User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.14; rv:65.0) Gecko/20100101 Firefox/65.0 Steps to reproduce: 1) Make some downloads 2) Quit Firefox 3) Start Firefox (e.g. next day, "bug" may not appear immediately after quitting) 4) Run in a extension the following JS code "var searching = browser.downloads.search({}); searching.then(function(r) { console.log(r.length); }); Actual results: The function "search({})" does not return all downloads. In my attached screenshot its just empty. Seems that Firefox shows only downloads made in current session or most recent downloads, but after a day everthing is gone. Expected results: It should be possible that the function returns the downloads as shown in Download Manager. E.g. in Chrome search({}) returns the same records as shown under "chrome://downloads", no matter the state or how old the records are.