SSH login getting terminated after entering user name

Hi All,
I am trying to login to the linux based device via SSH port i.e., 22 using putty. When trying to login, device is prompting for User name, but after entering to the device, ssh session terminates. Captured log using wireshark tool while performing this. Pasted below for your reference. Can anyone help me what would be a reason for this kind of behavior.

In this image, could see that device (IP address is sending FIN,ACK to the Client.