LangChain Token Usage Tracing Issue with VertexAI Model

from langchain_google_genai import ChatGoogleGenerativeAI
llm = ChatGoogleGenerativeAI(model="gemini-1.5-pro-001",
    temperature=0,
    max_tokens=None,
    max_retries=6,
    stop=None,)

from langchain_google_vertexai import VertexAI

# To use model
model = VertexAI(
            model="gemini-1.5-pro-002",
            temperature=0,
            max_tokens=None,
            timeout=None,
            max_retries=2,
            safety_settings=safety_settings,
            )

from openinference.instrumentation.langchain import LangChainInstrumentor

google.cloud.bigquery.opentelemetry_tracing.HAS_OPENTELEMETRY = False

if "PHOENIX_CLIENT_HEADERS" not in os.environ:
    try:
        with open(phoenix_api_path, "r") as file:
            api_key = file.read().strip()
            os.environ['PHOENIX_CLIENT_HEADERS'] = api_key
    except:
        os.environ["PHOENIX_CLIENT_HEADERS"] = getpass.getpass("Enter your Arize Phoenix API key: ")

tracer_provider = register(
  project_name="demo", # Default is 'default'
  endpoint="https://app.phoenix.arize.com/v1/traces",
)
LangChainInstrumentor().instrument(tracer_provider=tracer_provider)