User Agent: Mozilla/5.0 (Android 7.1.2; Mobile; rv:62.0) Gecko/62.0 Firefox/62.0 Build ID: 20180906142540 Steps to reproduce: 1. Install an addon that provides items in the main Firefox menu, such as Noscript, uBlock Origin or smart HTTPS. 2. Addon installs a menu item from which it does something for the page or site currently open. Actual results: Occasionally all menu items installed by add-ons have disappeared. They can be reinstated by disabling and re-enabling those add-ons individually. Expected results: Menu items installed by add-ons should be remembered and kept. This may be a duplicate of #882377 or related to it. That bug is five years old. I have had this problem for a very long time, but if I recall correctly, less than five years.

Should hopefully be fully fixed in Firefox 63.

If #1414084 means that opening a custom tab or PWA clears menu items so that they are lost when the browser is opened normally the next time, then this is a duplicate. Thanks.