HTTPS Request Not Working in Google App Engine (Python Requests lib) / Cloud Shell - google-app-engine

Question

I have been trying to do some html scraping for one of my projects, wherein the it is working from my local computer, but it is now working in google app engine. It is getting timed out.
I have tried using dig from google cloud shell, which is resolving the correct IP but still curl / trace is failing. Billing is enabled, haven't touched any DNS setting in GAE.
The target site is apparently using chunked reply.
from flask import Flask, render_template, request, send_file, redirect, url_for, Response, send_from_directory
import flask
import requests
import bs4
from requests.adapters import HTTPAdapter
from urllib3.util.retry import Retry
import logging
import os
s = requests.Session()
r = s.get("https://kdseodb.smportkolkata.in/ccuPomsPosWeb/index.jsp")
id1 = r.cookies['JSESSIONID']
r2 = s.get("https://kdseodb.smportkolkata.in/ccuPomsPosWeb/apps/dos/PosCTS.xhtml")
id2 = r2.cookies['oam.Flash.RENDERMAP.TOKEN']
headers = {'Accept': 'application/xml, text/xml, */*; q=0.01', 'Accept-Language': 'en-US,en;q=0.9', 'Connection': 'keep-alive', 'Content-Type': 'application/x-www-form-urlencoded; charset=UTF-8', 'Faces-Request': 'partial/ajax', 'Sec-Fetch-Dest': 'empty', 'Sec-Fetch-Mode': 'cors', 'Sec-Fetch-Site': 'same-origin', 'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/108.0.0.0 Safari/537.36', 'X-Requested-With': 'XMLHttpRequest', 'Cookie': 'JSESSIONID='+id1+'; oam.Flash.RENDERMAP.TOKEN=-'+id2+''}
payload = 'javax.faces.partial.ajax=true&javax.faces.source=form1%3AbtnSearch&javax.faces.partial.execute=form1&javax.faces.partial.render=form1&form1%3AbtnSearch=form1%3AbtnSearch&form1%3AcomMloCd_focus=&form1%3AcomMloCd_input=NONE&form1%3AtxtCntNo=ABCD1234567&form1%3AtblData_scrollState=0%2C0&form1_SUBMIT=1&javax.faces.ViewState=PCsvYkkMUQAmP0zfu2tj7G5AqM%2BXrDH8%2BaG%2FROvEtWIHJyXX'
r3 = s.post("https://kdseodb.smportkolkata.in/ccuPomsPosWeb/apps/dos/PosCTS.xhtml", cookies=r.cookies, headers=headers, data=payload)
soup = bs4.BeautifulSoup(r3.text)
dig output from google cloud shell, NXDOMAIN is coming up when used on the IPs
dig kdseodb.smportkolkata.in
; <<>> DiG 9.16.33-Debian <<>> kdseodb.smportkolkata.in
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 414
;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 1
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 512
;; QUESTION SECTION:
;kdseodb.smportkolkata.in. IN A
;; ANSWER SECTION:
kdseodb.smportkolkata.in. 3600 IN A 117.242.152.158
kdseodb.smportkolkata.in. 3600 IN A 203.153.37.38
;; Query time: 6 msec
;; SERVER: 169.254.169.254#53(169.254.169.254)
;; WHEN: Thu Dec 29 01:44:36 UTC 2022
;; MSG SIZE rcvd: 85
dig 117.242.152.158
; <<>> DiG 9.16.33-Debian <<>> 117.242.152.158
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 29831
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 512
;; QUESTION SECTION:
;117.242.152.158. IN A
;; AUTHORITY SECTION:
. 86400 IN SOA a.root-servers.net. nstld.verisign-grs.com. 2022122801 1800 900 604800 86400
;; Query time: 5 msec
;; SERVER: 169.254.169.254#53(169.254.169.254)
;; WHEN: Thu Dec 29 01:45:39 UTC 2022
;; MSG SIZE rcvd: 119
dig 203.153.37.38
; <<>> DiG 9.16.33-Debian <<>> 203.153.37.38
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 32307
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 512
;; QUESTION SECTION:
;203.153.37.38. IN A
;; AUTHORITY SECTION:
. 86400 IN SOA a.root-servers.net. nstld.verisign-grs.com. 2022122801 1800 900 604800 86400
;; Query time: 7 msec
;; SERVER: 169.254.169.254#53(169.254.169.254)
;; WHEN: Thu Dec 29 01:46:13 UTC 2022
;; MSG SIZE rcvd: 117