The title matching algorithm used in DOM distiller requires exact matching, except for the publisher that's stripped away. However, some sites uses slightly different titles in <title> and <h1>, causing the matching to fail.

Example: https://www-marketwatch-com.cdn.ampproject.org/v/www.marketwatch.com/amp/story/guid/E6CA6E62-F220-11E6-82ED-7800910FCE87?amp_js_v=7

What's in <title>:
Tesla could decide to tap capital markets as its shares rally analyst says - MarketWatch

What's in <h1>:
Tesla could decide to tap capital markets as its shares rally, analyst says

If edit distance is short enough, 1 in this example, then it should still match.