error GDAL_ERROR 1: b'PROJ: proj_create_from_database: crs not found' with custom CRS in spatial_ref_sys

[Alex]

Hi
situation with custom CRS in geodjango.

context: Debian GNU/Linux 12 (bookworm), Postgresql 16.6, Python 3.11.2, Postgis 3.4.2, GDAL 3.6.2, PROJ 9.1.1, Django 4.2.11, DRF 3.5.11, [DRF-GIS]​https://github.com/openwisp/django-rest-framework-gis 1.0

Objects with geometry in DB creates with no problem with this class

from django.contrib.gis.db import models

class Location(models.Model):
   ...
    c_geom = models.GeometryCollectionField(srid=300001)
   ...

gdalsrsinfo works as expected

gdalsrsinfo 'USER:300001'
PROJ.4 : +proj=tmerc ...

projinfo also works fine

projinfo 'USER:300001' 
PROJ.4 : +proj=tmerc ...

python manage.py shell is correct

from osgeo import osr
sk = osr.SpatialReference()
sk.SetFromUserInput('USER:300001')
0
print(sk)
PROJCS... 

but app always throws errors when fetch and create objects via API (in admin.site - ok, no errors)

def create(self, validated_data):
        if "SRID=300001;" in str(self.validated_data["geom"]):
            logger.info("*"*60)
            logger.info(f"validated_data geom with USER:300001: {self.validated_data['geom']}")
            logger.info(f"geom srid: {self.validated_data['geom'].srid}")
            from osgeo import osr
            sk = osr.SpatialReference()
            sk.SetFromUserInput('USER:300001') # <- here same error: GDAL_ERROR 1: b'PROJ: proj_create_from_database: crs not found'
            logger.info(f"SpatialReference: {sk}")
            logger.info("*"*60)

error.log

************************************************************
validated_data geom with USER:300001: SRID=300001;GEOMETRYCOLLECTION Z (POINT Z (83721.138 59266.787 101.09))
geom srid: 300001
GDAL_ERROR 1: b'PROJ: proj_create_from_database: crs not found'
SpatialReference: 
************************************************************
GDAL_ERROR 1: b'PROJ: proj_create_from_database: crs not found'
GDAL_ERROR 1: b'PROJ: proj_create_from_database: crs not found'
...

if request one object via API, Django send 8 email with this error. odd