User mention does not render with Blog Posts Excerpts option

The Blog Posts macro with Excerpts option does not render any user mention. It displays the contents in plain text.

Step To Reproduce

1. Create a blog post
2. Include user mention in the blog (i.e. @admin)
   
3. Create a page
4. Select Other Macros > Blog Posts macro
5. Set excerpts for Content Type to Display
6. Save and observe the result
   Make sure blog post and page are in the same space.

Expected Result

• It should render the user mention (i.e. @admin)

Observed Result

• It does not render the user mention (i.e. admin)