User login to the openVZ container or why does WinSPC fall off?

Question

Debian

The task is this, there is a main server on which there are several more virtual ones (openVZ containers).
It is necessary to make sure that when logging in via ssh, a certain user gets into his container.
Described this question here:
User @inkvizitor68sl kindly provided a good solution, but again there were problems, if you use the Patty client, then everything is fine, everything works.
However, if you use WinSPC, then this program falls off:

Cannot initialize SFTP protocol. Is the host running a SFTP server?

Please tell me what could be the problem?