In order to set up up of the comment box to show under each of your blog posts, please try the following:


1. In the Wix editor, click on the "My Blog" button on the left side of the screen, then click on "Blog Pages" and select the "Single Post" option:



You can read more about the Single Post page in the Wix Help Center.


2. Open the Wix app market, and add the Comments application to your "Single Post" page:



3. After adding the Comments app into your "Single Post" page, drag it over the content of you blog post. You may see a blue message saying "attach to box", depending on your blog template.


4. Use the Drag Handle to drag the Comments app below the text of your post. Drag it until the page expands to accommodate both the content of the post and the Comments app below it. 



5. Double click on the app to complete the setup.


You can see a recorded example of all the above steps in the following video we created:


https://www.youtube.com/watch?v=Lk-a97eJBsE


This should make the Wix Editor understand that the Comment box comes right after the text, even if the text is shorter / longer.