A new theme I'm building suddenly started showing every single post on the single.php and archive.php pages.
WP knows it's 'supposed' to be a single/archive page because it's showing the correct output in the sidebar (I have multiple conditional options: 'this is a post from...', 'this is the __ category archive' etc.), but it still shows all posts.
(Note: this is a test site, and the horizontal lines - if they're there - are for my layout.)
I'm an experienced WP user and I've never seen this before. Any suggestions? Much appreciated