I can't connect to my EC2 Instance that use Instance Store Volume

Hi

I am unable to connect to an EC2 Instance that uses Instance Store as Root (I tried EC2 connect). SSH is open all IPs, I have key pair (might not be required) I get message "unable to establish connection" or something to that effect. But when I try to connect with another EC2 Instance with EBS (GP3) and the same configuration as the other, it connects with no problem.

How do I connect to an Instance Store backed EC2 instance? Is there a additional configuration required?

Thank you!