Thanks for your report.
Please contact Wasabi support and ask them to fix their FTP interface.
Thanks Martin for your verification.
Is it possible to implement some workaround (e.g. in the configuration parameters) like: "Continue even if a directory listing fails" ?
My point is that WinSCP aborts the connection when this event happen.
Maybe some parameter might allow to connect anyway, despite a directory listing failed (and the directory is considered, necessarily, empty or not even shown)
Please note that it's totally clear to me that the problem is 100% server side, no doubt !
My point is since I don't think they will fix the server (they probably use some close solution to implement a virtual ftp filesystem over their cloud) maybe a simple workaround would be / is already possible in the configuration of the client. This is what, for example, YummyFTP for mac does.