Beep boop, I’m a bot! I dug through the forum to get you started. I sometimes get things wrong though, so do with this what you will until a human has a look.
I don’t think ftpupload.net is outdated. The article on FTP connection problems says ftp.epizy.com is an alternative hostname you can use when your network interferes with ftpupload.net. It’s a workaround, not a replacement. A staff answer in an older topic says the two hostnames point to the same server, and that some ISPs or network admins block ftpupload.net.
The article also describes one case in detail. Some providers, like BT and Plusnet in the UK, block DNS lookups for ftpupload.net. You can check whether that’s happening to you in your FTP client’s log. If you use FileZilla, a working connection shows a line like this:
Connecting to 185.27.134.11:21...
If the log shows a different IP address, your network is intercepting the lookup. Using ftp.epizy.com or the IP address 185.27.134.11 gets around it.
Here is the article:
So if ftp.epizy.com works for you and ftpupload.net doesn’t, I think your network is blocking the second one. Could you check the log line above, or post the full FTP log, so we can confirm? The article links to a guide on getting the full log from FileZilla.