That probably means you haven't gotten the "good" ending with Jake, then?
Jake is extra shy, so while he's easy to start dating, he's difficult to successfully date.
Try picking choices early on that also establish yourself as shy (like not greeting people as enthusiastically when you first meet them), and be more generally understanding and patient with him while actually dating him.
(Once you achieve a "good" ending on a route, you'll unlock the full set of features in that guy's profile.)