Since about three days ago, I keep seeing read posts on my feeds (local, all, etc)

I have disabled the switch to show read posts. I have also tapped the button that hides read posts. The posts appear as read, with a different font color in their title. But they are just not hidden.

I have checked the GitHub issue tracker and this community and have found no other person raising this issue. Therefore I assume I must be doing something wrong. But what? I have not touched my settings basically since I installed voyager. Did a recent update break the “hide read posts” behavior?