Shortcode To Display In Blog Post Widget

Not the best at explaining. But in the current Wordpress theme I am using, there is a widget I have on the home page by the theme developer that shows latest posts. That widget, among other things, takes the text in the "text/main content?" area and displays the it like an excerpt... because it only shows so much. Well, if I put a shortcode in that same text area, it displays nothing.

Now I found and went into the .php file and changed what was happening there to :: echo do shortcode('[actual-shortcode]'); and it will show.

So somewhere, somehow, something is coded to ignore the shortcode when it is in the text area. What I need to know I guess is what to replace (with what I replaced to test) in the php file to make sure the shortcode gets recognized when it is just in the text main content area of the post editor.

Thanks.