I think this can happen if the feed itself (the rss/atom file) has more articles than you specify. As far as I know this setting really only applies to articles it cached that are no longer visible on the feed.

thanks for this! interested in checking it out

Are you using fish as your login shell? I had a similar issue (though I was stuck on a black screen without a text cursor), and I think it was related to this issue https://github.com/sddm/sddm/issues/1592. I was using fish, ssdm, and trying to login to a wayland session.

The issue also does not exactly describe what you saw but I hope it's helpful. Unfortunately I don't have a solution myself, I swapped to using lightdm instead.