Server closed unexpectedly when transferring csv files

Connection is getting lost/disconnected when when transferring csv files. I tried with .txt file it worked fine. My transfer type is "binary".
Log attached.

As with your previous issue, this is most likely server-side bug.
For a start, I'd try to limit SFTP version to 3.
https://winscp.net/eng/docs/ui_login_sftp
Also, the log shows XLSX file upload, not CSV.
I can see that the problem occurs after WinSCP asked the server to rename the uploaded file from temporary name to the final one.
Maybe the server has broken rename functionality. Try to turn off Transfer to temporary file name, to avoid the rename:
https://winscp.net/eng/docs/ui_pref_resume