This is a highly requested feature and in the process of being implemented. I believe it will be available next update.
I had a feeling it was broken. Both active and new keep showing posts from 2-4 days ago. I’m still looking for an option to hide read posts but i found something that kind of works.
You can change your settings to not show read posts in your feed. Only problem is you gotta open the comments or upvote em. But it helps.
And right now New is definitely the way to go.
I would recommend to Lemmy to add something like top by hour or 12 hours as well, or something similar to the rising sorting with reddit. That might help things become less stale.
I enjoy seeing mau5trap rep