Are you getting better speed in any other SFTP client?
Also please read:
File transfer speed is very low. WinSCP does not utilize all available bandwidth. How do I improve the transfer speed?

Hello Team,

File transfer speed is very low as it is taking more than 24h to complete the job.
Please find below current configuration details:

1. Total File Size: (Download Data:13 GB) and (Upload Data: 12 GB)
   
2. Bandwidth: 250 MBPS
   
3. Protocol: SFTP
   
4. WinSCP Version 5.19.5
   

Till December 2021 the bandwidth was 100 MBPS and data transferred an expected, file size was 12GB and taken taken to complete the job is around 5 to 6 hours.
Later WinSCP took 24 Hours to complete the job and file size-download data is about 13GB and upload data is about 12 GB.

Note: We are running automation script on task scheduler, which was given by client.

Requesting you help to determine what is causing the issue in WinSCP.

Thanks in advance.