Not sure if this is isolated to me, but when sorting by Active, my Subscribed, Local and All feeds pretty much don't change for multiple days. I have to sort by New, Hot, etc. to get new content, but even those feeds stay somewhat constant.
Is this a problem with how the Lemmy feed algorithms work? Or is it a queueing issue, like how Mastodon refreshes timelines?
The algorithms I believe. Both active and hot are currently a bit broken, as are a few other things. Their biggest problem is they have trouble deprioritizing older posts, which leads to them getting more activity, keeping them high on the prioritization list. I've found sorting by new comments, new, and top (today) are really good ways to explore the site, and I've heard that the Lemmy devs are working on a fix for the broken algorithms. You can also hide read posts in your settings, though that has some drawbacks.
I think there's definitely some algorithm changes needed. I've noticed some weirdness with kbin's hot algorithm. In comments, it often puts comments with no votes or just one vote near the top, which doesn't make sense.
I also notice the front page hot algorithm has a duration option, but it doesn't seem to change anything.
And the top sorting looks like it might be local only?
This is an issue that the dev team is actively working on and (I believe) it'll be a part of the 0.18.0 release.
There's a hacky workaround some admins in the matrix chat implemented @TheDude@sh.itjust.works -- set a cron job to restart your lemmy back-end every hour or so. Not sure what the impact would be on a bigger instance like this but the restart only take a few seconds on my smaller one and it keeps my feeds fresh.
Lemmy is having growing pains and there are problems with internal tasks not updating the database correctly plus I'm sure individual instances would want to change some of these parameters to define what is 'active' in terms of age criteria, etc.
I've noticed similar stuff. My home page / active feed stays the same pretty much all day. I'll check it the next day and see some new content refreshed; probably a symptom of kbin being relatively "new" in terms of an influx of activity, so it likely won't be cycling through content as much as, say, Reddit may have been.
Who knows? Still, I'm happy to be here and looking forward to seeing this place grow more!
Reddit could be very stale over the course of a day too. The major difference is the depth was longer due to more content. I definitely had many days where I'd consumed everything in the reddit front page and had not much new there.