Michele, Slavek, All,
I just ran across a new bug on openSUSE Tumbleweed where the sftp_kio is completely broken. I suspect this is the result of the new openssh package and perhaps option changes, etc...
It's no little issue, attempting to connect in konqueror, kate, kwrite, etc.. with sftp://host/path/to/whatever -- coredumps.
This slunk in sometime in the past week or so along with new versions of openssh. I don't have smoking gun evidence it is openssh -- but that is my best guess based on recently updated packages. Tumbleweed has openssh-9.8p1 built last Friday.
Let me know if you see this in TDE, and if you don't, be on the lookout for it when openssh updates.