[Django]-Django charfield with default empty string is required in admin

I’m not sure why you think that’s a bug. If you don’t specify blank=True, some kind of non-empty value is required. The empty string, by definition, is an empty value; so Django quite correctly displays an error telling you to supply an actual value.

You do need to specify blank=True if you want the empty string to be allowed. But you don’t need to specify null=True; indeed, as the docs show, you shouldn’t use that on CharFields.