Django makemigrations: Makemigration not detect fields, only creates id filed

Question

my problem is about makemigrations, it not detect fields and only creates id and foreignkey field. I added studentapp to INSTALLED_APP:

INSTALLED_APPS = [
'django.contrib.admin',
'django.contrib.auth',
'django.contrib.contenttypes',
'django.contrib.sessions',
'django.contrib.messages',
'django.contrib.staticfiles',
'studentapp.apps.StudentappConfig'
]

and models.py has: from django.db import models

class Department(models.Model):
    name = models.CharField(null=True, ),
    active = models.BooleanField(default=True),



    def __str__(self):
        return self.name


class  Student(models.Model):
    department = models.ForeignKey(Department, on_delete=models.CASCADE, 
    related_name="students", default=None)
    name = models.CharField(max_length=50, default=None, null=True, blank=True),
    date_born = models.DateField(),
    hobbi= models.CharField(max_length=100,),
    active = models.BooleanField(default=True),


    def __str__(self):
       return self.name

then I run command: python manage.py makemigrations studentapp result of command:

Migrations for 'studentapp':
  studentapp\migrations\0001_initial.py
    - Create model Department
    - Create model Student

newly created migration files (0001) only have id field and foreignkey field. code in migrations 0001:

# Generated by Django 4.0.3 on 2022-04-03 08:03

from django.db import migrations, models
import django.db.models.deletion


class Migration(migrations.Migration):

    initial = True

   dependencies = [
    ]

   operations = [
        migrations.CreateModel(
            name='Department',
            fields=[
            ('id', models.BigAutoField(auto_created=True, 
   primary_key=True, serialize=False, verbose_name='ID')),
        ],
    ),
    migrations.CreateModel(
        name='Student',
        fields=[
            ('id', models.BigAutoField(auto_created=True, 
  primary_key=True, serialize=False, verbose_name='ID')),
            ('department', models.ForeignKey(default=None, 
  on_delete=django.db.models.deletion.CASCADE, 
  related_name='students', to='studentapp.department')),
        ],
    ),
  ]