Thanks for the suggestion this would be a good workaround. However I was successful with full TLS connection setting

cert_cn = 'host.docker.internal'
    options = (
        ('grpc.ssl_target_name_override', cert_cn,),
               )
    with open("/workspace/skills/authorization/certs/ca.pem", "rb") as fp:
        ca_cert = fp.read()
    credentials = bearer_token_credentials(token="somerandomkeyhere", certChain=ca_cert)
    client = Client(
        "spicedb:50051",
        credentials,
        options=options
    )