I push a wio terminal version.
It isn’t well documented, so I try to explain the first handshake.
Fist you must configure the Filezilla (or other ftp client) as described in my article relative to the library
https://www.mischianti.org/2020/02/08/ftp-server-on-esp8266-and-esp32/
than after the first login hand shake in FTPServer.cpp (or after a refresh if you are previously connected) MLSD command is called check line from 515 ti 535, but the problem start on openDir at 519 line tha call lines from 909 to 941, STORAGE_MANAGER define
#define STORAGE_MANAGER SD
try to call open of directory /, but the resulting File “dir” on dir.openNextFile(); get 0 value and so no files are loaded.
But If you instantiate
File dir2 = SD.open("/");
and than try
dir2.openNextFile();
you can get the files.
I think It’s a scope problem, but I need time to discover It.
Thank Renzo