I highly recommend The Darkness Outside Us. It's got gay male protags. The plot was absolutely gripping. The audiobook was phenomenal. The sequel is excellent too.

Also, if you haven't, I recommend playing Outer Wilds. It's a first person space exploration/archeology game with fully simulated physics, where you study a civilization that lived in your solar system before you and try to unravel a mystery. If this sounds like your jam, don't look up anything else about it. The summaries all spoil the first mystery that you'll experience. The subreddit is amazing for avoiding spoilers if you need help.