Contrast between file creation via EC2 Instance Connect & SSH Client

Using a bastion server can solve many problems but the medium you take to connect to your bastion can introduce some problem. One such problem that I encountered is when I was on my bastion server and created ".pem" file to connect to my private EC2 using EC2 Instance Connect. On SSHing, it asked me to enter passphrase. Which I was never asked on any ssh client. So I tried to use other SSH client (CloudShell in my case) to login to the bastion server. On the bastion, I created ".pem" file to connect to my private EC2. Guess what? I was not asked to enter PassPhrase this time. So I compared both the ".pem" files to check what could be the issue, but still I cannot figure out what the issue is. I request my fellow community to shed some light to the problem. I am attaching details on both the files below - -r-------- 1 root root 1699 Dec 26 19:12 MyKey.pem [on EC2 Instance Connect] -r-------- 1 root root 1675 Dec 26 19:15 MyKey.pem [on SSH Client - CloudShell]