Django rest framework nested serialization not working properly

If you are just sending IDs then you don't need to add the nested serializer, just specify the field name of the ForeignKey or ManyToManyField.

class WriteTeacherSerializer(serializers.ModelSerializer):

    class Meta:
        model = Teacher
        fields = ('phone_number', 'bio', 'price', 'disciplines', 'schedules')

I am also wondering if it is because you have a depth=1 flag?

DRF doesn't support nested updates out of the box. You have to override the Serializer's update method, and write your own update logic, so you'd be seeing an error for this warning if you were sending nested data.