The following tiddler is text/markdown type has html tag with WikiText. Only the third one can correctly render into links (i.e. with new empty lines after html tag).
HTML blocks are ultimately parsed by the WikiText parser: an opening tag followed by a blank line will activate block-level parsing for its content. When working with tags designed to contain literal content, such as <pre> and <style> tags, refrain from adding blank lines after the opening tags.