Django Admin Not Displaying `creation_date` Field Despite Being in `list_display`

I have a Django project where I'm working on an e-commerce application. I'm using SQLite as my database, and I'm trying to add a creation_date field to my VendorProduct model so that it records when a product was created.

What I Did

I added the creation_date field to my VendorProduct model like this:

models.py (VendorProduct Model)

from django.db import models
from django.utils.timezone import now
from userauths.models import CustomUser

class VendorProduct(models.Model):
    user = models.ForeignKey(CustomUser, on_delete=models.SET_NULL, null=True, blank=True)
    creation_date = models.DateTimeField(auto_now_add=True, blank=True, null=True)

    def __str__(self):
        return self.title

Migrations

I ran the following commands to apply the migration:

python manage.py makemigrations vendorpannel
python manage.py migrate vendorpannel

Then, I verified that the creation_date column exists in my database using:

from django.db import connection

with connection.cursor() as cursor:
    cursor.execute("PRAGMA table_info(vendorpannel_vendorproduct);")
    columns = cursor.fetchall()

for column in columns:
    print(column)

The output confirms that creation_date exists in my database:

(7, 'creation_date', 'datetime', 0, None, 0)

Admin Panel Configuration

I updated my admin panel to display creation_date:

admin.py

from django.contrib import admin
from .models import VendorProduct

class VendorProductAdmin(admin.ModelAdmin):
    list_display = ('creation_date')  
    readonly_fields = ('creation_date',) 

admin.site.register(VendorProduct, VendorProductAdmin)

Problem: creation_date Not Showing in Django Admin

Even after making these changes and applying migrations, the creation_date field is not appearing in the Django admin panel under list_display.

What I Tried

1. Checked if the field exists in the database using SQL queries (confirmed ✅).
2. Cleared Django cache and restarted the server:

   python manage.py collectstatic
   python manage.py runserver
   

3. Checked if the field name is correct in list_display (confirmed ✅).
4. Verified that list_display works for other fields (other fields display correctly, just creation_date is missing ❌).

Expected Outcome

• I expect to see creation_date displayed in the Django admin panel under VendorProduct.
• The field should be read-only and should not be manually editable.

Question

Why is creation_date not appearing in the Django admin panel, even though:

• It exists in the database.
• It's correctly added in list_display.
• Migrations were applied successfully.

What am I missing here?

creation_date = models.DateTimeField(default=datetime.now, blank=True)