Does Spectrum block attempts to connect to the FTP server on the tp-link Archer c7. My FileZilla log has this response:
Status: Connecting to 172.27.35....:21
Status: Connection established, waiting for welcome message...
Error: Could not connect to server
Did you already have static IP / and DNS manager service setup, And don't forget port forward to the FTP IP. Have you tried SFTP instead?