Failing Tableau Cloud Connected App JWT Signin

I am trying to generate a JWT and using it to sign-in to Tableau Cloud using REST API. My code used to work, but is not since a few days, and its throwing error (16) and 401001. I am using Connected Apps Direct Trust for REST API authentication. Please also note that I am the Site Administrator Creator of my site, and using "Initial Google" for login into Tableau account. 

As per the official documentation, its most likely related to exp or sub claim, and I have verified that all the information I am providing is correct. The Connected App is enabled, and its details are also correct. Here's my Python code: 

import datetimeimport uuidimport jwtimport requests# =========================# JWT CONFIG# =========================BASEURL = "https://10ax.online.tableau.com"SITE = "userful"# =========================# JWT CONFIG# =========================CLIENT_ID = "XXX"SECRET_ID = "YYY"SECRET_VALUE = "ZZZ"USER = "bhavyai.gupta@userful.com"AUDIENCE = "tableau"SCOPES = [    "tableau:views:embed"]# =========================# GENERATE JWT# =========================current_time = datetime.datetime.now(datetime.timezone.utc) - datetime.timedelta(seconds=5)token = jwt.encode(    payload={        "iss": CLIENT_ID,        "exp": current_time + datetime.timedelta(minutes=5),        "jti": str(uuid.uuid4()),        # "nbf": int((datetime.datetime.now(datetime.UTC) - datetime.timedelta(seconds=5)).timestamp()),        "iat": datetime.datetime.now(datetime.timezone.utc) - datetime.timedelta(minutes=2),        "aud": AUDIENCE,        "sub": USER,        "scp": SCOPES,    },    key=SECRET_VALUE,    algorithm="HS256",    headers={        "kid": SECRET_ID,        "iss": CLIENT_ID,        "alg": "HS256"    })print(f'JWT: {token}')# =========================# TABLEAU SIGN-IN REQUEST# =========================url = BASEURL + "/api/3.28/auth/signin"headers = {    "Accept": "application/json",    "Content-Type": "application/json"}payload = {    "credentials": {        "jwt": token,        "site": {            "contentUrl": SITE        }    }}response = requests.post(url, json=payload, headers=headers)# =========================# RESPONSE HANDLING# =========================print(f"\nStatus Code: {response.status_code}")try:    print(f"Response JSON: {response.json()}")except ValueError:    print(f"Response Text: {response.text}")

The exact 

error

 response I am receiving is this: 

Status Code: 401 

Response JSON: {'error': {'summary': 'Signin Error', 'detail': 'Error signing in to Tableau Server (16)', 'code': '401001'}} 

Any help is greatly appreciated. Thank you!!!