cannot connect to one of the two instances on the same VCN subnet using its public IP

Summary:

I created two compute instances on the same VCN public subnet. Both were assigned a public IP. I am able to connect to one of the instances without issue. However, when I attempt to connect to the other from the same client (so I have the same ssh public/private key on both instances), I get a "no route to host" error. Not sure why that would be the case because both the instances are on the same subnet (have the same route tables, security list, etc)

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