Problem with ftp directory format in response to a PHP NLIST instruction.

Hi everyone, I hope someone can help. This is an FTP IOT related question. We are moving a IOT management portal from a web server to a VPS. The VPS is all setup and working but we are getting an incorrect FTP Native response to a PHP NLIST command:
/public_ftp/bin9/..
/public_ftp/bin9/.
/public_ftp/bin9/Filename_0,12.bin
The original website gave this correct FTP Standard response to the same command:
.
..
Filename_0,12.bin
The field devices are programmed to parse the file name from this response where the path names are not included (second example). Parsing is failing on the new VPS response due to the incorrect FTP Native Directory Format. I have spent many weeks Googling this problem without success. I have also tried many different Ubunto, Centos, Apache, Nginx, and different FTP server combinations without success. Our VPS is currently setup with Ubunto 16.04, Nginx 1.15 and PureFTP . I cannot find any configuration option that will select the FTP Standard Directory format where the directory path is not included and only file names listed. I hope someone out there can help as I’m now really stuck with this problem.