https://en.wikipedia.org/w/index.php?title=Leapfrog_sex_position&action=edit does not have a monospace textarea when it should. This applies to both the MonoBook and Vector skins. I think semiprotected pages aren't getting the appropriate CSS class in the HTML output. Semiprotected pages get class="mw-textarea-sprotected" while it should probably be class="mw-textarea-sprotected mw-editfont-monospace"?
Compare with the talk page, which is not semiprotected and has a monospace textarea: