Tried that - failed with the same error.
I also figured it might be worth trying with auto adjusted encryption - that produced the following stderr:
Exception in Task: System.Exception: Failed to upload file: E:\env\prod\data\outgoing\201911_BSB_input2.csv to /BSB/In to Callcredit/201911_BSB_input2.csv, err: SBSftpCommon.EElSFTPError: SFTP component not connected
at VisualCronService.ProcessTaskFTPClass.UploadSFTPFiles(ConnectionClientClass cc, FTPCommandClass fc, List`1 localFiles, String strDestinationFolder, Int32& intTotalFiles, ConnectionHandlerClass ch, Boolean bolDebugging) in C:\git\code\VisualCronService\Jobs\TaskProcesses\Net\FTP\clsProcessTaskFTP.vb:line 2562