All server support staff aren't aware of this issue, and recently we hear the repeated complaint
I asked my server support team about my problem, and they said that they don't have a problem - so Blogger has to be the cause of the problem. What is Blogger doing about my problem?
Many times, the diagnosis from the server support team is coming from their first level support staff. My observation has been that, frequently, the first priority of the first level support staff is to ensure that they have no problem, and to inform the customer that they have to go elsewhere (ie to Blogger Support) for relief of their problem.
That being the case, and assuming that you want your problem fixed, it's now your job to ask for diagnostics. Here, a server console log (showing the flow of the FTP process, from the server perspective), and the server firewall logs (showing rejected traffic, from the server perspective), from the time period when you tried publishing, will be most useful.
Some times, the second level server support staff, whom you will be in contact with after the first level staff tells you to go complain to Blogger Support, will examine the logs and identify the problem on their own. Other times, you may have to peruse the logs yourself. In either case, you will get nowhere until you explicitly request access to the logs.
And that's persistence. In one case, persistence required 3 weeks of insisting.
However long it takes, it starts with you.