I’m currently obsessed with colonization narratives. I hope you pursue this.

I love stories about mysteriously disappeared civilizations and ancient runs on far away planets. This sounds like it's the beginning of a great story.

An abandoned world without stars or a sun, reachable only by a specially built gate, is colonized by humanity.  They find another inactive gate there.  After several years, the gate activates, and the gate to Earth is cut off.  No one has heard from the colonization team since.