node.js markdown blog : when edit blog'a article have blank space

Question

the tutorial video: https://www.youtube.com/watch?v=1NrHkjlWVhM&t=2693s

github: https://github.com/godzillalogan/markdownblog

my blog: https://gentle-inlet-86339.herokuapp.com/

I have a blog in node.js and framework express.js, i use the way of the the tutorial video to install the markdown blog. but have a problem.

original the article in my blog

but when every time I edit the article

It always has blank space in front of every paragraph.

I don't know if it's my way of store the article is wrong or using HTML textarea has problem.

thank you for your help

edit articles in routes/modules/admin.js:

//edit article
router.put('/articles/:id', upload.single('image'), async (req, res)=>{

  try{
    const _id = req.params.id
    const { title,description,markdown,category } = req.body
    const { file } = req // 把檔案取出來
    const article = await Article.findOne({ _id})
    if (file){
        // const filePath = await imgurFileHandler(file) // 把檔案傳到 file-helper 處理 
        imgur.setClientID(IMGUR_CLIENT_ID)
        imgur.upload(file.path,async (err, img) =>{
        // Article.update({...req.body, image: file ? img.data.link: article.image})
        article.title = title
        article.description = description
        article.markdown = markdown
        article.category = category
        article.image = img.data.link
        await article.save()
        })
    }else{
      article.title = title
      article.description = description
      article.markdown = markdown
      article.category = category
      await article.save()
    }
    res.redirect('/admin/articles')
  }catch(e){
    console.log(e)
    res.redirect(`/admin/articles`)
  }
  // const {title,description,markdown} = req.body   //和new一樣才能將markdown轉成html
  //   Article.create({...req.body})
  //   res.redirect('/')
})

views/edit:

<div class="container">
    <div class="row grid">
      <div>
        <nav class="userSidebar fixed mt-3">
          <div class="buttonList mt-5">
            <div class="navItem index d-flex mb-4">
              <div class="icon d-flex align-items-center color-blue">
                <i class="fas fa-home my-auto"></i>
              </div>
              <a href="/admin/articles" class="btn">
                <span class="fs-5 fw-bolder color-blue">文章清單</span>
              </a>
            </div>
            <div class="navItem userProfile d-flex mb-4">
              <div class="icon d-flex align-items-center">
                <i class="fas fa-users"></i>
              </div>
              <a href="/admin/users" class="btn">
                <span class="fs-5 fw-bolder">使用者列表</span>
              </a>
            </div>
            <div class="navItem userProfile d-flex mb-4">
              <div class="icon d-flex align-items-center">
                <i class="fas fa-users"></i>
              </div>
              <a href="/admin/categories" class="btn">
                <span class="fs-5 fw-bolder">種類列表</span>
              </a>
            </div>
            <a href="/admin/logout" class="btn">
              <span class="fs-5 fw-bolder">登出</span>
            </a>
          </div>
        </nav>
      </div>
      <div>
        <h1 class="mb-4">Edit Article</h1>
        <form action="/admin/articles/{{article._id}}?_method=PUT" method="POST" enctype="multipart/form-data">
          {{>formFields}}
        </form>
      </div>
    </div>
  </div>

views/partials/formFields.hbs:

<div class="form-group mb-3">
  <label for="title">Title</label>
  <input require value="{{article.title}}" type="text" name="title" id="title" class="form-control">
</div>
<div class="form-row mb-3">
  <label class="form-label" for="image">Image</label>
  <input  class="form-control" type="file" class="form-control-file" id="image" name="image">
</div>
<div class="form-group mb-3">
  <label for="category">category</label>
  <select name="category" id="category" class="form-control">
    {{#each categories}}
      <option value="{{this.categoryEnName}}"  
      {{#ifCond this.categoryName ../article.category}}
         selected
       {{/ifCond}}>
       {{this.categoryName}}
      </option>
    {{/each}}
  </select>
</div>
<div class="form-group mb-3">
  <label for="title">Description</label>
  <textarea name="description" id="description" class="form-control">{{article.description}}</textarea>
</div>
<div class="form-group">
  <label for="markdown">Markdown</label>
  <textarea required name="markdown" id="markdown" class="form-control" rows="15" cols="80">{{article.markdown}}</textarea>
</div>
<a href="/admin/articles" class="btn btn-secondary mt-3">Cancel</a>
<button type="submit" class="btn btn-primary mt-3">Save</button>