I use Firefox too and the same applies to my site on the button to download the backup of the database. The file it is not downloaded.
Furthermore, the file/folder permissions now are shown like this: /.htaccess recommended 644 /index.php recommended 644….. That is, the recommended level is higher than usual permissions but I keep the old ones and everything is working fine.
Server Type: Apache
Operating System: Linux
WP Filesystem API Method: direct
Server API: cgi-fcgi CGI Host Server Type