Hi!
Weirdly, when I changed the redirection method on the General Options -> Behavior panel from “Post” to “Get”, I’m not seeing the 404 pages anymore. At least I’m not able to re-create it.
I’ve changed the post numbers to 7, 8, 9 and 10 for testing on the WP settings page, but still everything went okay for search phrases like “test a”, “run”, “mile”.
Can you confirm if this is the case? If not, than can you tell me what exact configuration (number of posts) and search phrase do I need to look at?