Why is the image still not appearing?

Question

The Page

So it appears that some images are being shown but others nada. Why?

Code` app.config['UPLOAD_FOLDER'] = UPLOAD_FOLDER app.config['MAX_CONTENT_LENGTH'] = 16 * 1024 * 1024

#Image Handleing
ALLOWED_EXTENSIONS = set(['png', 'jpg', 'jpeg'])

def allowed_file(filename):
    return '.' in filename and filename.rsplit('.', 1)[1].lower() in ALLOWED_EXTENSIONS

        
@app.route('/Detect')
def upload_form():
    return render_template('upload_image.html',title='Update', year=datetime.now().year)

@app.route('/Detect', methods=['POST'])
def upload_image():
    if 'file' not in request.files:
        flash('No file part')
        return redirect(request.url)
    file = request.files['file']
    if file.filename == '':
        flash('No image selected for uploading')
        return redirect(request.url)
    if file and allowed_file(file.filename):
        filename = secure_filename(file.filename)
        file.save(os.path.join(app.config['UPLOAD_FOLDER'], filename))
        #print('upload_image filename: ' + filename)
        flash('Image successfully uploaded and displayed below')
        return render_template('upload_image.html', filename=filename,title='Detection', year=datetime.now().year)
    else:
        flash('Allowed image types are -> png, jpg, jpeg, gif')
        return redirect(request.url)

@app.route('/display/<filename>')
def display_image(filename):
    #print('display_image filename: ' + filename)
    return redirect(url_for('upload_image', filename='/uploads/' + filename), code=301)

<!--
<h1 class="jumbotron">Image Classification</h1>
    <br><br>
    <div class="row">
      <div class="col-auto col-md-4 mx-auto">
        <form class="form-horizontal" action="/Detect" method="post" enctype="multipart/form-data">
    
          <div class="mb-3">
              <label for="" class="form-label"></label>
              <input type="file" name="file" id="" class="form-control" placeholder=".png, .jpeg etc..." aria-describedby="helpId">
              <small id="helpId" class="text-muted">Upload Your Image</small>
          </div>
          <br>
          <input type="submit" value="Upload" class="btn btn-success">
          
        
        </form>
      </div>
      <div class = "col-md-4 col-auto mx-auto">
        {% if filename %}
          <img src="{{ url_for('display_image', filename=filename) }}" />
        {% endif %}
      </div>
-->

`

In Addition it doesn't even give me a 404 on the terminal it just gives me 200 and maybe 304 as an insult. here are image of that Mock Me, Mocks Me again...

Please tell me I am doin something wrong or is it a bug?