This seems that FTP is breaking at the point it’s switching to passive mode. Passive mode is good for almost all clients. However, some routers try to be “smart” and will try to “fix” FTP, and end up breaking it completely because of this.
This article has a few methods that may help:
The FTP ALG section in the article would be the best way to solve it. Alternatively, you could try to connect over a VPN instead to bypass your router messing with the FTP connection.
Also:
I completely agree. Please configure FileZilla to use “FTP over Explicit TLS” instead. You can configure this from the Site Manager (found under the File menu in the top bar). The Quickconnect will try to determine the best setting by default, which should be explicit TLS. But if there is a router or firewall in between that’s hijacking your FTP connection, your FTP connection may not be secure.