For some reason setting the post_type query variable to page doesn’t have the desired effect. Other post types (post, custom post types) work, but page doesn’t do anything.
This is not a Relevanssi bug, but a WordPress feature (see this trac ticket). If the user inputs a bad value to the post_type query variable, WordPress changes it to any. For some reason that happens also when the post_type is set to page, even though that should be a valid value.
There’s nothing Relevanssi can do about this. However, there’s a fix. Relevanssi introduces a new query variable post_types, which happily accepts page. Use that, if you need to filter by post type.
(Update 19.1.2021: This WordPress bug still isn’t fixed!)
