The FTP server functionality stopped working recently. Version 1.1.19, running on iOS 11.4.1. No ftp client was able to connect to the phone with the ftp server switch active and the screen kept on, the connections simply timed out. No client isolation features has been enabled on the router, and vlc’s http server works just fine on the same device. Using nmap to scan the iPhone’s IP address says the ftp port is “filtered”.

Could there be a bug in the application?