I'm counting 25. And that's weird, because I was thinking it was perhaps instance dependent. But we're both on sh.itjust.works so it's not that... Is it always 23? I'm gonna try counting again tomorrow and see if I get 25 posts again.
Update: after writing the above comment, I went to my "home" feed. And that actually does load more posts freely without timeout. Maybe it's only in the "all" feed there's an issue?