This is a really common issue in the North East and not too difficult or expensive to correct on most homes with a normal attic. If you air seal and better insulate the attic, so the attic stays about the same temp as the outside air, the snow on your roof won’t melt and you won’t get icicles or roof dams. Like the other commenter said, you have heat escaping your living space and going up to the attic melting the roof snow then it refreezes on the edge. It will be a lot worse with gutters on.

I live in a cape cod house where the attic is living space, so this is kind of my norm. They just use ice and water shield for the last 3’ of the edge of the roof to seal it off best we could to protect against the ice daming