try to fix

app/helpers/admin/application_helper.rb

@@ -60,13 +60,14 @@ module Admin::ApplicationHelper
                 form: form.options.dig(:html, :id)
   end
 
-  def prepare_for_github(html)
+  def prepare_for_github(html, university)
     text = html.to_s
     text = sanitize text,
                     tags: %w(table a figure img figcaption i em b strong p h2 h3 h4 h5 h6 blockquote),
                     attributes: %w(href alt title target rel src srcset width height)
     text.gsub! "\r", ''
     text.gsub! "\n", ' '
+    text.gsub! "/rails/active_storage", "#{university.url}/rails/active_storage"
     sanitize text
   end
 

app/views/active_storage/blobs/_blob.html.erb

 <figure class="attachment attachment--<%= blob.variable? ? "preview" : "file" %> attachment--<%= blob.filename.extension %>">
   <% if blob.image? %>
-    <%= kamifusen_tag blob, width: 800, active_storage_direct_url: true %>
+    <%= kamifusen_tag blob, width: 800 %>
   <% elsif blob.video? %>
     <video>
       <source src="<%= rails_blob_path(blob) %>" type="<%= blob.content_type %>">
     </video>
   <% else %>
-    <%= link_to polymorphic_url(blob), target: :blank do %>
+    <%= link_to polymorphic_path(blob), target: :blank do %>
       <p>
         <span class="attachment__name"><%= blob.filename %></span>
         <span class="attachment__size"><%= number_to_human_size blob.byte_size %></span>

app/views/admin/communication/website/authors/jekyll.html.erb

@@ -5,6 +5,6 @@ first_name: "<%= @author.first_name %>"
 last_name: "<%= @author.last_name %>"
 slug: "<%= @author.slug %>"
 biography: >
-  <%= prepare_for_github @author.biography %>
+  <%= prepare_for_github @author.biography, @author.university %>
 ---
 <%= @author.github_frontmatter.content.html_safe %>

app/views/admin/communication/website/categories/jekyll.html.erb

@@ -4,6 +4,6 @@ slug: "<%= @category.slug %>"
 identifier: "<%= @category.id %>"
 parent: "<%= @category.parent_id %>"
 description: >
-  <%= prepare_for_github @category.description %>
+  <%= prepare_for_github @category.description, @category.university %>
 ---
 <%= @category.github_frontmatter.content.html_safe %>

app/views/admin/communication/website/pages/jekyll.html.erb

@@ -7,8 +7,8 @@ parent: "<%= @page.parent_id %>"
 image: "<%= @page.featured_image.blob.id %>"
 <% end %>
 description: >
-  <%= prepare_for_github @page.description %>
+  <%= prepare_for_github @page.description, @page.university %>
 text: >
-  <%= prepare_for_github @page.text %>
+  <%= prepare_for_github @page.text, @page.university %>
 ---
 <%= @page.github_frontmatter.content.html_safe %>

app/views/admin/communication/website/posts/jekyll.html.erb

@@ -13,8 +13,8 @@ categories:
 image: "<%= @post.featured_image.blob.id %>"
 <% end %>
 description: >
-  <%= prepare_for_github @post.description %>
+  <%= prepare_for_github @post.description, @post.university %>
 text: >
-  <%= prepare_for_github @post.text %>
+  <%= prepare_for_github @post.text, @post.university %>
 ---
 <%= @post.github_frontmatter.content.html_safe %>

app/views/admin/research/researchers/jekyll.html.erb

@@ -3,5 +3,5 @@ title: "<%= "#{ @researcher }"%>"
 first_name: "<%= @researcher.first_name %>"
 last_name: "<%= @researcher.last_name %>"
 biography: >
-  <%= prepare_for_github @researcher.biography %>
+  <%= prepare_for_github @researcher.biography, @researcher.university %>
 ---