451-Error when uploading to Siteground FTP

[jonasskafte]

Describe the bug
For a while now I've had to revert to using FileZilla whenever I wanted to upload folders any larger than approx 5 MB. I get an error message saying: "451-Error during read from data connection".

I've recently wiped my computer and done a clean install of MacOS and Cyberduck, but unfortunately that didn't fix the problem. I was hoping it would!

My FTP is hosted by Siteground.

This issue is, and has been for a good while, rendering Cyberduck kind of useless to me, to be honest. I much prefer using Cyberduck, but I've had to revert to FileZilla which doesn't throw this issue.

I've tested uploading to Flywheel via SFTP and that went through fine. So I'm guessing it has to do with Siteground's server specifically – however, it's strange that FileZilla doesn't throw the same error?!

Hope someone can help me and please let me know if you have any questions!

Thanks!

To Reproduce
Steps to reproduce the behavior:

1. Try and upload a semi-large folder to a Siteground FTP.

Expected behavior
A completed upload like in the good ol' days.

Screenshots

Desktop (please complete the following information):

• OS: Sequoia
• Version 15.5

Log Files
REMOVED

Additional context
Add any other context about the problem here.

[jonasskafte]

UPDATE!:

With help from Siteground support I worked out that the connection had to be in 'Active (PORT)' mode. Just trying to work out why that is now as I'd expect it to be Passive mode if anything (not that I know much about these things!).

I'll keep this thread updated till I've got to the bottom of it.