Windows Server 2012 r2 firewall settings for FTP in active mode

I suggest you try to locally on the server using Windows' FTP or another installed client. This way you will see if it's network/firewall issue or an issue with the configuration of the FTP server. Also check Filezilla server's log files if the commands.

If it depends on the firewall, here is a TechNet article that could help: How to Configure Windows Firewall for a Passive Mode FTP Server. But you wrote that the Windows firewall is off, so I suppose it is a problem of the external firewall/router (also check the client side).

FTP server and FTP client negotiates which ports are going to be used for the transfer of data (including the directory list when you do a "dir" or "ls") using the "control channel" of FTP. So if your "AWS firewall" is not doing protocol inspection on this channel there is no way he will know which ports it has to dynamically open to allow the traffic flow (and close once those ports are not longer used).

IMHO using network monitoring to discover which ports are being used is not worth the effort because these ports are going to change for every new FTP session.

Unless you have already done it, my best shot at troubleshooting this issue would be to look for any tweak on the firewall that is protecting your FTP server (if I understand your question correctly this would be the "AWS firewall") and see if there is any "knob" to enable inspection for the FTP protocol.