Connection lost while transfering by FTPS.

While transfering files by (Implicit) FTPS session is disconnected around 100 files completion. Nothing is problem if using FTP and SFTP.

WinSCP version: 5.13.6
Windows version: Windows10 [10.0.17134.472]
Server: vsftpd-3.0.2@CentOS7

Is there anything useful in server log file? Did you test the same using any other FTPS client?