My solution:
Change
if soup.title.string in ["Citrix Gateway", "NetScaler AAA", "Digital Workplace", "NetScaler Gateway"]:
title_check = True
logging.info(f"{url} - Title Check Passed")
to
title = soup.title.string.strip() if soup.title and soup.title.string else None
if title in ["Citrix Gateway", "NetScaler AAA", "Digital Workplace", "NetScaler Gateway"]:
title_check = True
logging.info(f"{url} - Title Check Passed")