javascript - Trumbowyg not formatting text (Bold, Italic, Strikethrough) -

i'm using trumbowyg wysiwyg text editor http://alex-d.github.io/trumbowyg/

the buttons i'm using bold, italic, strikethrough , insertimage. right now, button works insertimage. when select text , apply bold, italic or strikethrough, nothing. when post submitted, doesn't render bold, italic or strikethrough. plain text. keep in mind rendered post has safe template filter:

{{instance.content|safe}} 

when remove safe, doesn't render formatting renders actual html this:

<strong>text</strong> 

regardless of this, when making post text editor doesn't format properly:

**bold text** 

it this:

bold text 

the thing renders insertimage. when insert image shows immediately, , renders fine after posting.

any idea why other formatting doesn't work?