FTP Access Failed - 502 Command SITE Not Implemented

Hi,

I'm having issues with FTP uploads to Box.

Context: I'm using a DIY Raspberry-Pi-based field recording device to continuously capture 6-channel audio in 20min segements and upload the compressed FLAC files (and corresponding log files) to Box.

The device runs the following scripts, which use 'lftp' to mirror the upload directory on the device to the designated FTP server: https://github.com/BeckyHeath/multi-channel-rpi-eco-monitoring/tree/master -- see in particular 'ftp_upload.sh' which is called within 'python_record.py', lines 209-247.

I trialled this during a previous deployment of the device for a month between Oct. and Nov. last year (2023) and it worked without issues. 

Problem: I re-deployed the device on Feb 13th. I did a brief trial the night before (12th Feb.), during which two audio files were captured and successfully uploaded, alongside the first part of a backlog of files that had accumulated in late Nov. and Dec. last year during which the device continued to record in offline mode.

However, on 13th Feb., when the device was re-deployed to run continuously (ideally for over a month), the device successfully uploaded more of the backlog of files, but failed to upload any of the new files that were being recorded in real time. This issue continued for the next couple of days - on each day, a new directory for that day would be created in Box, but no new files would upload, nor would any log files. The three day deployment should have been plenty of time for the full backlog of files to upload and for the files of new recordings to upload too. 

I retrieved the device yesterday to inspect its behaviour more closely. When connected to a screen, I noticed the following error messages printing in the terminal: 

chmod: Access failed: 502 Command SITE not implemented for CHMOD. (./*log file or audio file name here*)

chmod: Operation not supported: MFF and SITE CHMOD are not supported by this site

Despite these errors, some files still managed to upload yesterday. However, a number of files still failed to upload altogether.

As the scripts running my device haven't changed since my previous successful deployment (which uploaded to Box with no issues), I assume this is a problem on Box's end? I am unfortunately not familiar with the SITE or MFF commands, so not entirely sure what the exact issue is. However, my understanding of the 502 error code is that this is an issue with the server not supporting a command sent by the client, and as mentioned the commands being sent from my device should be no different to those sent during successful uploads in the past.

Is Box aware of this FTP issue -- and have any other users experienced this, recently or in general? Was something changed on the server-side of my account to prevent/limit further uploads (perhaps after the large volume of uploads from the file backlog)?

I would greatly appreciate any assistance with this issue ASAP, as I would ideally like to deploy more of these devices in the coming weeks. 

Please note that my Box account is linked my University's Enterprise account, so I do not have full access the Admin settings. I also access my account through SSO and therefore had to set a dedicated 'external' password for FTP login, which I have not changed and is still the password that my device is set to use. 

Thanks in advance!