调用Binance期货API返回-2015错误：Invalid API-key, IP, or permissions for action的排查求助

我现在碰到了Binance期货API的权限问题，返回错误{'code': -2015, 'msg': 'Invalid API-key, IP, or permissions for action, request ip: ...'}，想请大家帮忙排查下问题所在。

我是按照Binance官方的签名示例代码来实现的，已经确认过几个关键点：

• API密钥和密钥是正确复制的，没有输入错误
• 当前请求的IP地址已经正确添加到API密钥的白名单中
• 这个API密钥是在我开通期货账户之后才创建的

以下是我的完整代码：

import hashlib
import hmac
import time
from urllib.parse import urlencode
import requests
import cred

KEY = cred.KEY
SECRET = cred.SECRET

BASE_URL = "https://fapi.binance.com"  # production base url
# BASE_URL = "https://testnet.binancefuture.com"  # testnet base url

def hashing(query_string):
    return hmac.new(
        SECRET.encode("utf-8"), query_string.encode("utf-8"), hashlib.sha256
    ).hexdigest()

def get_timestamp():
    return int(time.time() * 1000)

def dispatch_request(http_method):
    session = requests.Session()
    session.headers.update(
        {"Content-Type": "application/json;charset=utf-8", "X-MBX-APIKEY": KEY}
    )
    return {
        "GET": session.get,
        "DELETE": session.delete,
        "PUT": session.put,
        "POST": session.post,
    }.get(http_method, "GET")

# used for sending request requires the signature
def send_signed_request(http_method, url_path, payload={}):
    query_string = urlencode(payload)
    # replace single quote to double quote
    query_string = query_string.replace("%27", "%22")
    if query_string:
        query_string = "{}&timestamp={}".format(query_string, get_timestamp())
    else:
        query_string = "timestamp={}".format(get_timestamp())
    url = (
        BASE_URL + url_path + "?" + query_string + "&signature=" + hashing(query_string)
    )
    print("{} {}".format(http_method, url))
    params = {"url": url, "params": {}}
    response = dispatch_request(http_method)(**params)
    return response.json()

# get account informtion
# if you can see the account details, then the API key/secret is correct
response = send_signed_request("GET", "/fapi/v2/account")
print(response)

我实在找不出哪里出问题了，有没有朋友能帮我分析下可能的原因？

备注：内容来源于stack exchange，提问作者advortsov