For information logs are below for andFTP and lftp, if helpful you can connect to ftp.sdalu.com in anonymous mode (login: ftp)
= andFTP =
= lftp =220 ProFTPD 1.3.3 Server (ProFTPD) [::ffff:91.121.152.207]
AUTH TLS
234 AUTH TLS successful
USER sdalu
331 Password required for sdalu
PASS ****
230 User sdalu logged in
PBSZ 0
200 PBSZ successful
PROT P
200 Protection set to Private
CWD /
250 CWD command successful
SYST
215 UNIX Type: L8
PASV
227 Enterring Passive Mode (91,121,152,207,205,123)
LIST
150 Opening BINARY mode data connection for file list
425 Unable to build data connection: OPeration not permitted
<--- 220 ProFTPD 1.3.3 Server (ProFTPD) [::ffff:91.121.152.207]
---> AUTH TLS
<--- 234 AUTH TLS successful
---> USER sdalu
<--- 331 Password required for sdalu
---> PASS XXXX
<--- 230 User sdalu logged in
---> PWD
<--- 257 "/" is the current directory
---> PBSZ 0
<--- 200 PBSZ 0 successful
---> PROT P
<--- 200 Protection set to Private
---> PASV
<--- 227 Entering Passive Mode (91,121,152,207,218,64).
---- Connecting data socket to (91.121.152.207) port 55872
---- Data connection established
---> LIST
<--- 150 Opening BINARY mode data connection for file list
---- Got EOF on data connection
---- Closing data socket
<--- 226 Transfer complete