150 Starting data transfer. and hangs on LIST command

[JMFUS]

Hello
I fixed my certificates problems and now I can connect to the Filezilla Server :

I have the message : 150 Starting data transfer and nothing else
I checked my firewall authorizations on my server (I tried without firewall too)
I'm in Passive mode
But I can't read the contents of the directory on my server with the following code :

    def retrlines(self, cmd, callback=None):
        """Retrieve data in line mode.

        A new port is created for you.

        Args:
          cmd: A RETR, LIST, or NLST command.
          callback: An optional single parameter callable that is called
                    for each line with the trailing CRLF stripped.
                    [default: print]

        Returns:
          The response code.
        """
        if callback is None:
            callback = print

        self.sendcmd('TYPE A')
        
        print("========= retrlines - ftplib : cmd : ", cmd)
        
        with self.ntransfercmd(cmd)[0] as conn:
            print("========= retrlines - ftplib : OK ")
            
            data = conn.recv(1024)  # Lire 1024 octets du socket (ajustez la taille selon vos besoins)
            
            print("========= retrlines - ftplib : conn (raw data):", data)
            
            if hasattr(conn, 'makefile'):
                print("========= retrlines - ftplib : makefile ")
                fp = conn.makefile('rb')
                print("========= retrlines - ftplib : makefile (suite)")
            else:
                fp = conn._sock

            n = 1
            while True:
                print("========= retrlines - ftplib : while true => " , n)
                n = n+1
                line = fp.readline(MAXLINE + 1).decode()
                
                print("========= retrlines - ftplib : line : ", line)

                if not line:
                    print("========= retrlines - ftplib : not line ")
                    break

                if len(line) > MAXLINE:
                    raise Error("got more than %d bytes" % MAXLINE)

                if self.debugging > 2:
                    print('*retr*', repr(line))

                if line[-2:] == CRLF:
                    line = line[:-2]
                elif line[-1:] == '\n':
                    line = line[:-1]

                callback(line)
                
            print("========= retrlines - ftplib : while false")
            
            # shutdown ssl layer
            if _SSLSocket is not None and isinstance(conn, _SSLSocket):
                conn.unwrap()

            fp.close()
            print("========= retrlines - ftplib : close")
            
        return self.voidresp()

items = []
ftp_conn.retrlines("LIST",items.append)

In fact, that's this command which hangs : data = conn.recv(1024) # Lire 1024 octets du socket (ajustez la taille selon vos besoins)
And I don't have any more information

Someone could help me ?

As a reminder, I'm working with a Raspberry Pi Pico WH (RP2040) with the Micropython version 1.22.0

Thx in advance

[robert-hh]

How far does it get? Is any print() statement of the above code run?

[JMFUS]

Yes, it prints : print("========= retrlines - ftplib : OK ")
And it hangs on: data = conn.recv(1024) # Read 1024 bytes from the socket (adjust the size according to your needs) for a long time until timeout
It never prints :
print("========= retrlines - ftplib : conn (raw data):", data)