I am attempting to use FTP proxy from a Linux server using FTP command

I have Single Sign On enabled for FTP proxy on my BM3.7 box - this is
used by a number of windows clients utilising FTP_Voyager & clntrust.

When I attempt to open an FTP connection to the BM server I get 550 No
access. If I switch FTP proxy authentication to 'None' or 'clear text
user/password' I can connect from the Linux server but my FTP_Voyager
clients stop working.

Is it possible to configure Bordermanager to allow both single sign on
and prompted sign on (Clear text user/password) thus allowing both my
windows clients and this linux client access through the proxy.