Hi, thank you for your reply.
First of all, I am really sorry for discontinuing support for the FTP server feature at this moment. This is because there were many issues regarding the support for the FTP server.
One of the main issue was related to the Unicode support: since iOS had been used to use Apple File System (APFS) as the internal file system of the iOS devices, a lot of problems had been raised regarding the Unicode support.
I also tried to use open-source libraries such as pureftpd, but it also had the same issue.
Another solution on my side is to implement the FTP server feature by myself (by writing a code purely in Swift or Objective-C). I still keep this as a valid option, because many users, including you and even me, loved the FTP server feature. But I suspect that it may take a lot of time to implement this with considering the Unicode issue, so I did not include this in the current version.
About the issue in the browser-based Wi-Fi file transfer feature, thank you so much for reporting that issue! The fix will be included in the next update.
Sorry for the inconvenience again about the current circumstances of the FTP server feature.