No Internet connection when running a Python script

[snippsat]

Some improvement,like time.sleep(blocking) is not the best for schedule stuff.
So schedule and loguru(great) for logging.

import requests
import os
from bs4 import BeautifulSoup
import time
from loguru import logger
logger.add("log_file.log", rotation="2 days")
import schedule
try:
    from lxml import etree
except ImportError:
    raise RuntimeError("Please install lxml with `pip install lxml`")

URL_TO_MONITOR = "https://hckrnews.com/"
CHECK_INTERVAL = 15

def process_html(site_content):
    soup = BeautifulSoup(site_content, features="lxml")
    # Combining tag selections
    for s in soup(["script", "meta"]):
        s.extract()
    return str(soup).replace("\r", "")

def webpage_was_changed():
    headers = {
        "User-Agent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/39.0.2171.95 Safari/537.36",
        "Pragma": "no-cache",
        "Cache-Control": "no-cache",
    }
    response = requests.get(URL_TO_MONITOR, headers=headers)
    if not os.path.exists("previous_content.txt"):
        open("previous_content.html", "w+").close()
    with open("previous_content.html", "r+") as filehandle:
        previous_response_html = filehandle.read()
        processed_response_html = process_html(response.content)
        if processed_response_html != previous_response_html:
            filehandle.seek(0)
            filehandle.write(processed_response_html)
            filehandle.truncate()
            return True
    return False

def check_webpage():
    try:
        if webpage_was_changed():
            logger.info("WEBPAGE WAS CHANGED.")
        else:
            logger.info("Webpage was not changed.")
    except Exception as e:
        logger.exception(e)

def main():
    schedule.every(CHECK_INTERVAL).seconds.do(check_webpage)
    logger.info("Running Website Monitor")
    while True:
        schedule.run_pending()
        time.sleep(1)

if __name__ == "__main__":
    main()

Also a tips i would say that soup.prettify() is broken,make new lines in tag so dos look like standard HTML at all.
Use Prettier have a command line tool so do just prettier --write . in folder then get correct formatted HTML.