we have tried both and got the same issue (gunicorn vs uvcorn).
No I meant creating a

@router.post(
    "/sleep",
    tags=["temp"],
    response_description="Return HTTP Status Code 200 (OK)",
    status_code=status.HTTP_200_OK,
    response_model=TestResponse,
)
# def here instead of async def
def post_sleep(time_sleep: float) -> TestResponse:
    """ """
    time.sleep(time_sleep)
    return TestResponse(status="OK")