Looks like your ftp client doesn’t listen very well to the LITERAL PASV command, it keeps setting up the connection from port TCP 20 to you…
Good to hear you found a solution, and had some fun with wireshark 
:-TU
Well I did read somewhere that command prompt ftp doesn’t have real support for passive mode, but I don’t know how true that is.
Yeah wireshark was actually quite fun
Well based on the packet capture you posted very true, that’s not the way Passive FTP works