django.core.exceptions.FieldError: Related Field got invalid lookup: relation_type

[Jonas Kiefer]

Hi folks,

i implemetned the following models:

```python

class MetadataRelation(models.Model):
id = models.UUIDField(default=uuid.uuid4, primary_key=True)
from_metadata = models.ForeignKey('Metadata', on_delete=models.CASCADE, related_name='from_metadatas')
to_metadata = models.ForeignKey('Metadata', on_delete=models.CASCADE, related_name='to_metadatas')
relation_type = models.CharField(max_length=255, null=True, blank=True,

class Metadata(Resource):

...

related_metadatas = models.ManyToManyField('self', through='MetadataRelation', symmetrical=False, related_name='related_to+', blank=True)

```

I want to filter a queryset of `Metadata` objects by the related field called `relation_type` like: `Metadata.objects.filter(
metadata_type=MetadataEnum.SERVICE.value,
is_active=True).exclude(related_metadatas__relation_type=MetadataRelationEnum.HARVESTED_THROUGH.value) django raises django.core.exceptions.FieldError: Related Field got invalid lookup: relation_type.

Why i can't use the related fields as filters if i use the through argument for the m2m field?

greetings

Jonas