Thanks, I will ask them about whitelisting my ranges. They cannot be whitelisting every individual IP address one by one, their support staff would be doing nothing else.
The FTP logs in and gets as far as retrieving a directory listing before timing out. When they whitelist my IP, the directory listing succeeds.
Especially annoying considering the ticket response times, one reply took three days. https://imgur.com/zqQIRXt