It's not exactly like Star Trek to be sure, but it's possible you might enjoy continuum. Definitely deals with moral issues, but it's not space based, or as futuristic

Black mirror, especially the early seasons

So I’m totally taken in by the Chinese series Three Body. Technically it fits the description of “humans interacting with aliens” but nothing like Star Trek. Well, humans are united & at peace with each other but boy-howdy is it dark stuff when it comes to alien-human interaction. And it’s hard sci-fi. Like, the aliens will take centuries to get here.

I’ve been listening to The Fade. Sun trilogy audiobook by C J Cherryh.

The best way to describe it in Star Trek terms is if imagine that Kazon were hired by Romulans to act as mercenaries to fight the Federation. Except the Romulans are giant blobs. And the story is mainly told from the Kazon perspective.

What about star Trek books? There's hundreds of them.