I'm using Ubuntu Mate 22.04, Firefox 106.0.1 SNAP install. I setted to TRUE the option browser.download.start_downloads_in_tmp_dir , when I open a document from a web page like .docx or .xlsx I can see the window that ask me how to manage the file, if I choice to open it (not download), Firefox present the option "Open with System Handler (default)" but nothing happens. Please remember that if I download the file and double click it, Libreoffice is called and opens the file. If I select "Choose other" Firefox opens an empty list of apps. In settings I can't change the option "System default". How can I fix this?