Django override settings not being assigned in the __init__ method even though they are available

I am overriding settings for the entire test class like this:

@mock_aws
@override_settings(
        AWS_CLOUDFRONT_DOMAIN="fake_domain",
        AWS_CLOUDFRONT_KEY="fake_key",
        AWS_CLOUDFRONT_KEY_ID="fake_key_id",
        AWS_CLOUDFRONT_DISTRIBUTION_ID="fake_distribution_id",
    )
class TestCloudfrontClient(TestCase):
    def setUp(self):
        self.cf_client = CloudfrontClient()

and here is the CloudfrontClient class:

class CloudfrontClient:
    """Client to interact with AWS S3 through Cloudfront"""
    
    def __init__(
        self, 
        cloudfront_pk_id=settings.AWS_CLOUDFRONT_KEY_ID,
        cloudfront_key=settings.AWS_CLOUDFRONT_KEY,
        cloudfront_distribution_id=settings.AWS_CLOUDFRONT_DISTRIBUTION_ID,
        cloudfront_domain=settings.AWS_CLOUDFRONT_DOMAIN,
        rsa_signer=rsa_signer
    ):
        self.cf_client = client('cloudfront')
        self.distribution_id = cloudfront_distribution_id
        self.cloudfront_signer = CloudFrontSigner(cloudfront_pk_id, rsa_signer)
        self.cloudfront_domain = cloudfront_domain
        breakpoint()

At the breakpoint if I print settings.AWS_CLOUDFRONT_KEY_ID I get the fake_key_id but when I print cloudfront_pk_id I get empty string. This is also the case for other variables and it is messing my test results. Am I missing something about how override_settings work?