Able to SSH into EC2 instance but with in fraction of second it closed by remote host. Facing problem frequently

I am using git bash also the Security group setting is fine. I have opened all traffic.The SSH connection are not even connected for 1 minute. After one command run it closed.

$ dateFri, Apr  3, 2020  5:06:05 PM$ ssh -i "test.pem" ec2-user@ec2-34-213-206-215.us-west-2.compute.amazonaws.comLast login: Fri Apr  3 11:35:50 2020 from 157.45.23.118       __|  __|_  )       _|  (     /   Amazon Linux 2 AMI      ___|\___|___|https://aws.amazon.com/amazon-linux-2/1 package(s) needed for security, out of 7 availableRun "sudo yum update" to apply all updates.[ec2-user@ip-172-31-24-125 ~]$ Connection to ec2-34-213-206-215.us-west-2.compute.amazonaws.com closed by remote host.Connection to ec2-34-213-206-215.us-west-2.compute.amazonaws.com closed.$ dateFri, Apr  3, 2020  5:06:24 PM

Could someone please assist.