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

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

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