dwhite wrote:M6 seems to misquote the external IP, this makes connecting to anything impossible.
And why do you think so? What exactly do you see in filezilla's message log area for your connection attempt? See
https://wiki.filezilla-project.org/FileZilla_Client_Tutorial_(en)#Connecting_to_a_server for some description on the various window areas in filezilla. Do you use a connection that is saved in site manager, or do you always enter IP/hostname, username and such each time?
I've just tested filezilla under mga6 and it works just fine, I tested with an FTPS server. As you don't provide any actual details on the connection you're trying to establish can't really help you any further unless you provide some actual details or at least a few bits of essential information needed to help you.
Please remember, other people can only help you as far as you provide a meaningful problem description an some actual details. If the only thing is "it doesn't work" then there's only so much others can do apart from basic troubleshooting hints.