Infinite Scroll/Pagination not working on the "Posts Page"

Infinite scroll works fine on archive pages and on the homepage. It even works on the pages using the Ajax Load More plugin. But when creating a new page and setting it as the "Posts Page" in Wordpress's Settings > Readings, both infinite scroll and pagination do not work. I can only see as many posts that are set in the Reading Settings. I could set this to view all the posts, but this would create an excessive DOM. Also when attempting to click to the next page, I'm sent to the "oops! page cant be found" page. Is infinite scroll/pagination not set to work on a custom posts page?