Just looking at it, but is the source for the comment’s repeating group a field that is a list of comments? If it is, you have two options to fix this:
Add another action is the create comment workflow to add the newly created comment to the page’s list of comments.
Or the other option
Change the repeating group data source to do a search for comments and set the post to the current page post.
Without seeing the app, I think those are the options that could fix it.