new posts not showing up when viewing communities directly?

Not sure if this is user error, a lemmy issue, a jerboa issue, or just inactive communities. A lot of communities I'm subscribed to, with many active members, show no posts more recent than a week or a month. At first I thought this was just a lack of activity, but recently I noticed that a post I had commented on was not visible from the community page (under either hot or new), although I was still getting replies and the post is visible from my comments page.

As a test, I tried posts from /all/, and was quickly able to find one that is visible for me from /all/ but does not appear on its own community page under new - the post on politics@lemmy.world about a 271 page document on Vance (about an hour ago).

All I can think is that either a lot of posts are being deleted (but somehow still showing up through other methods), or the community pages on jerboa are not updating even when explicitly told to refresh, either by dragging down from the top or selecting refresh from the community options menu.

Anyone else encountering this problem or know what might be causing it? I've noticed the lack of posts on subscribed communities for a while and always assumed the communities were just inactive (which obviously makes lemmy much less useful for me), but the politics test is making me think it's something else.

Edit: another point of reference, the newest post showing for me on this community (jerboa) is from a week ago, regarding switching language on gboard.