Django error value too long for type character varying(50)

I get the error below when I try to add a new article to my site

value too long for type character varying(50)
Request Method:	POST
Django Version:	4.0.4
Exception Type:	DataError
Exception Value:	
value too long for type character varying(50)
Exception Location:	/opt/venv/lib/python3.8/site-packages/django/db/backends/utils.py, line 89, in _execute
Python Executable:	/opt/venv/bin/python
Python Version:	3.8.16
Python Path:	
['/app',
 '/opt/venv/bin',
 '/nix/store/9493ngfjwisjm5f5s5ld5m34rdy431ic-python3-3.8.16/lib/python38.zip',
 '/nix/store/9493ngfjwisjm5f5s5ld5m34rdy431ic-python3-3.8.16/lib/python3.8',
 '/nix/store/9493ngfjwisjm5f5s5ld5m34rdy431ic-python3-3.8.16/lib/python3.8/lib-dynload',
 '/opt/venv/lib/python3.8/site-packages',
 '/opt/venv/lib/python3.8/site-packages/odf',
 '/opt/venv/lib/python3.8/site-packages/odf',
 '/opt/venv/lib/python3.8/site-packages/odf',
 '/opt/venv/lib/python3.8/site-packages/odf',
 '/opt/venv/lib/python3.8/site-packages/odf',
 '/opt/venv/lib/python3.8/site-packages/odf',
 '/opt/venv/lib/python3.8/site-packages/odf']
Server time:	Sun, 23 Apr 2023 10:10:10 +0000

Here is my models.py file content

class EnglishArticle(models.Model):
    author = models.ForeignKey(Author, related_name='author',on_delete=models.SET_NULL, null=True) 
    slug = models.SlugField()
    title = models.CharField(max_length=400)
    body = RichTextUploadingField(default='Empty Content')
    date_created = models.DateField()
    published = models.BooleanField(default=False)
    image = models.ImageField(blank = True, null = True)
    reading_time = models.IntegerField()
    views = models.IntegerField(default=0)

    class Meta:
        verbose_name_plural = 'Articles'

    def __str__(self):
        return self.title

    def save(self, *args, **kwargs):
        
        title = self.title.lower()
        x = ['@', '#', '?', "/", ".", ",", "&", "!","|","-","_"]
        z ="".join(filter(lambda char: char not in x, title)) 
        self.slug = re.sub(r"\s+", '-', z)
        super().save(*args, **kwargs)
    


class FrenchArticle(models.Model):
    title = models.CharField(max_length=400)
    body = RichTextUploadingField(default='Empty Content')
    french_article = models.OneToOneField(
        EnglishArticle,
        related_name="french_article",
        blank=True,
        null=True,
        on_delete=models.CASCADE)

    class Meta:
        verbose_name_plural = 'French Articles'    


    def __str__(self):
        return self.title