SSH Keys attached to custom image

Hi,

I hope that this is the correct forum for my questions.

I am attempting to create a custom image from an instance that I deployed. I have had issues deploying instances from this new custom image. For the instance, I generate private/public keys. What I discovered is that the keys that I generated from the original instance was preserved and baked into the new custom image. So when I deploy an instance form this custom image, the keys that I generate do not work. If I use the keys from the original instance, it works. I hope this is not confusing.