Hi Booberoi,
Thanks for getting back to us with those additional details. Your security is a priority for everyone at Apple, and we can understand how seeing these alerts could be confusing and disheartening.
Big Sur introduced a new security feature to alert you if your password details have appeared in known data leaks. If you recently updated to Big Sur, then this feature is making you aware of areas of concern to help you protect your accounts and your identity.
As explained in the link below, “iPhone also securely monitors your passwords and alerts you if they appear in known data leaks. If you don’t want iPhone to perform this monitoring, go to Settings > Passwords > Security Recommendations, then turn off Detect Compromised Passwords.”
Follow this link to learn more about this new feature:
Change a weak password on iPhone
Don’t hesitate to reach out if you have any additional questions. We’re here for you.