Recent DSS output files are not found in SFTP reports folder.

The existing DSS user (Narrative Tapestry, DSS ID:9039653 ) developed their own SFTP system and is currently testing it. They could log in DSS normally and retrieve data from the reports directory, but the files they are expecting are not there. They can only find files some time ago, and recent files are missing according to the user. Please find attached screenshot from the client and advise what the possible issues would be. Are there any DSS parts which would cause such issue? Even this would be a client issue, please also advsie what they can do to solve the issue.