uuid field not properly recognized

[e-belair]

Hi, I have the following database schema:

CREATE TABLE AGDE_ETAB
(
  ETAB_ID D_UUID,
  DENOMINATION VARCHAR(255) NOT NULL,
  VOIE_ID D_UUID,
  CONSTRAINT AGDE_ETAB_PK PRIMARY KEY (ETAB_ID),
)

CREATE TABLE AGDE_VOIE
(
  VOIE_ID D_UUID,
  NOMRUE VARCHAR(100),
  CONSTRAINT AGDE_VOIE_PK PRIMARY KEY (VOIE_ID),
);

The D_UUID field is a domain type field like
Char(16) CHARACTER SET OCTETS
NOT NULL
COLLATE OCTETS

My Python models is like this:

import uuid 

from django.db import models 

class AgdeEtab(models.Model): 
    etab_id = models.UUIDField(primary_key=True, default=uuid.uuid4, blank=False, null=False) 
    activite_commerce = models.ForeignKey('AgdeActiviteCommerce', models.DO_NOTHING, blank=True, null=True) 

    class Meta: 
        managed = False 
        db_table = 'agde_etab' 

class AgdeVoie(models.Model):
    voie_id = models.UUIDField(primary_key=True, default=uuid.uuid4, blank=False, null=False) 

    class Meta:
        managed = False
        db_table = 'agde_voie'
        unique_together = (('commune', 'codevoie'),)

In console, if I try to get the related AgdeVoie from Etab I get an error:

from agde.models import AgdeEtab
. . . etab = AgdeEtab.objects.get(enseigne__startswith='MIDAS')
. . . etab.voie

Traceback (most recent call last):
  File "/home/manu/env01/fbtest/venv/lib/python3.6/site-packages/django/db/models/fields/related_descriptors.py", line 158, in __get__
    rel_obj = self.field.get_cached_value(instance)
  File "/home/manu/env01/fbtest/venv/lib/python3.6/site-packages/django/db/models/fields/mixins.py", line 13, in get_cached_value
    return instance._state.fields_cache[cache_name]
KeyError: 'voie'
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
  File "<input>", line 3, in <module>
  File "/home/manu/env01/fbtest/venv/lib/python3.6/site-packages/django/db/models/fields/related_descriptors.py", line 164, in __get__
    rel_obj = self.get_object(instance)
  File "/home/manu/env01/fbtest/venv/lib/python3.6/site-packages/django/db/models/fields/related_descriptors.py", line 139, in get_object
    return qs.get(self.field.get_reverse_related_filter(instance))
  File "/home/manu/env01/fbtest/venv/lib/python3.6/site-packages/django/db/models/query.py", line 397, in get
    num = len(clone)
  File "/home/manu/env01/fbtest/venv/lib/python3.6/site-packages/django/db/models/query.py", line 254, in __len__
    self._fetch_all()
  File "/home/manu/env01/fbtest/venv/lib/python3.6/site-packages/django/db/models/query.py", line 1182, in _fetch_all
    self._result_cache = list(self._iterable_class(self))
  File "/home/manu/env01/fbtest/venv/lib/python3.6/site-packages/django/db/models/query.py", line 53, in __iter__
    results = compiler.execute_sql(chunked_fetch=self.chunked_fetch, chunk_size=self.chunk_size)
  File "/home/manu/env01/fbtest/venv/lib/python3.6/site-packages/django/db/models/sql/compiler.py", line 1068, in execute_sql
    cursor.execute(sql, params)
  File "/home/manu/env01/fbtest/venv/lib/python3.6/site-packages/django/db/backends/utils.py", line 100, in execute
    return super().execute(sql, params)
  File "/home/manu/env01/fbtest/venv/lib/python3.6/site-packages/django/db/backends/utils.py", line 68, in execute
    return self._execute_with_wrappers(sql, params, many=False, executor=self._execute)
  File "/home/manu/env01/fbtest/venv/lib/python3.6/site-packages/django/db/backends/utils.py", line 77, in _execute_with_wrappers
    return executor(sql, params, many, context)
  File "/home/manu/env01/fbtest/venv/lib/python3.6/site-packages/django/db/backends/utils.py", line 85, in _execute
    return self.cursor.execute(sql, params)
  File "/home/manu/env01/fbtest/venv/lib/python3.6/site-packages/django/db/backends/firebird/base.py", line 262, in execute
    return self.cursor.execute(q, params)
  File "/home/manu/env01/fbtest/venv/lib/python3.6/site-packages/fdb/fbcore.py", line 3677, in execute
    self._ps._execute(parameters)
  File "/home/manu/env01/fbtest/venv/lib/python3.6/site-packages/fdb/fbcore.py", line 3349, in _execute
    self.__tuple2xsqlda(self._in_sqlda, parameters)
  File "/home/manu/env01/fbtest/venv/lib/python3.6/site-packages/fdb/fbcore.py", line 3132, in __tuple2xsqlda
    len(value)))
ValueError: Value of parameter (0) is too long, expected 16, found 32

The first problem is that I get an incorrect validation, the max_length should be 32 so I should not get this error. How I can avoid this?

The second problem is that if I comment this part of the code in the driver, I get an SQL error because the where clause is incorrect.
Instead of having WHERE voie_id = 'abcd123', I should get WHERE voie_id = x'abcd123'
like hexadecimal notation: https://firebirdsql.org/refdocs/langrefupd25-hexbinstrings.html
So how i can custom the where clause in the generated parameter or is there another way to get it working?