How do I list only one instance of each comment?

I have an admin dashboard that takes the comments from all of the blog posts and lists them so I can manage them easier. The problem is it shows a second instance of comments left as a reply which makes it a bit cluttered. How do I stop it from listing replies twice? This isn't an issue when they render in the post's view.

How I call the list in my user.show view:

<%= render(partial: 'comments/comment', collection: @comments) %>

users_controller (show method): @comments = Comment.all

_comment.html.erb partial:

<div class="wellington top-drop">
  <h3 class="title-top align-left"><%=h comment.name %><% if comment.admin_comment == true %><span class="text-muted"> | Admin</span><% end %></h3>
  <% if current_user.present? && current_user.admin? %>
  <%= link_to "Delete", comment, method: :delete,
                                  data: { confirm: "Are you sure you want to delete this comment? This will delete all replies to this comment." },
                                  class: "btn btn-xs btn-danger align-right" %>
  <p class="align-right text-muted pad-right"><%= comment.updated_at.strftime('%b %d, %Y') %></p>
  <% end %>
  <div style="clear: both;"></div>
  <p class="nobot align-left"><%=h comment.body %></p> <!-- the h breaks down html tags into plain text -->
  <button type="button" class="btn btn-xs btn-success align-right" data-toggle="collapse" data-target="<%= "#collapse#{comment.id}" %>" aria-expanded="false" aria-controls="<%= "collapse#{comment.id}" %>">Reply</button>
  <div style="clear: both;"></div>
  <div class="collapse" id="<%= "collapse#{comment.id}" %>">
    <%= simple_form_for([comment, Comment.new]) do |f| %>
    <%= render 'shared/error_messages', object: f.object %>
      <%= f.input :body, :as => :text, input_html: { maxlength: 300 }, label: false, placeholder: "What are your thoughts?", class: "form-control", wrapper_html: { id: 'contactTextarea' } %>
      <%= f.input :name, label: false, placeholder: "Name (required) - Just your first name is okay too!", class: "form-control" %>
      <%= f.input :email, label: false, placeholder: "Email Address (required) - This is not displayed with the comment", class: "form-control" %>
      <div class="form-group hidden">
        <%= f.input :nickname, :hint => "leave this field blank!", class: "form-control" %>
      </div>
      <%= f.submit "Reply", class: "btn btn-success" %>
    <% end %>
  </div>
</div>

<ul>
  <%= render partial: 'comments/comment', collection: comment.comments %>
</ul>

This is what it looks like:

EDIT: I don't have this issue when rendering them in their respective post's view - only when it's being rendered in the user's show view.

I am handling my comments through a polymorphic relation:

CommentsController:

before_action :find_commentable

private

def find_commentable
  @commentable = Comment.find_by_id(params[:comment_id]) if params[:comment_id]
  @commentable = Post.friendly.find(params[:post_id]) if params[:post_id]
end

Comment Model:

class Comment < ApplicationRecord
  belongs_to :commentable, polymorphic: true
  belongs_to :user, optional: true
  has_many :comments, as: :commentable, dependent: :destroy
  default_scope {order(created_at: :asc)}
  attribute :nickname, :captcha  => true
  validates :body, presence: true, length: { minimum: 3, maximum: 300 }
  validates :name, presence: true, length: { minimum: 2, maximum: 30 }
  VALID_EMAIL_REGEX = /\A[\w+\-.]+@[a-z\d\-]+(\.[a-z\d\-]+)*\.[a-z]+\z/i
  validates :email, presence: true, length: { maximum: 100 },
                    format: { with: VALID_EMAIL_REGEX }

  def admin_comment
    user&.admin
  end

end