iCloud Keychain passwords appearing on different users device

I have the exact same issue. However, I have my own Apple ID and set up my phone with this account. Later, a family member shared their iCloud storage subscription plan (iCloud+) with me as they had a lot more storage space than I. My family member also has their own Apple ID and never have we used the same Apple ID across any of our devices although the iCloud storage is now the same. I can't seem to find any resources to address this problem. Ideally, I would like my passwords to remain on my device and my family member's to be removed from my device in the passwords section under settings.

Are you sharing an AppleID?

If all your devices are sharing a common AppleID for iCloud, you’ll encounter all kinds of issues with unintentional and/or unwanted sharing of sensitive/private information (including your Keychain). You’ll not be able to reliably maintain any kind of data separation.

The Golden Rule: Don’t share an AppleID between users. Each user should have their own AppleID for their own exclusive use - linked to their own primary email (and secondary/recovery email addresses and trusted telephone numbers). 

You would be best advised to separate your digital identities and configure a new AppleID for your spouse, or yourself, as appropriate.

After separating your identities, you can continue to selectively share purchased Apple Services, Subscriptions, Apps and Media using Apple’s Family Sharing features - should you choose to do so.

Family Sharing - Apple

Set up Family Sharing – Apple Support

Share App Store, iTunes Store and Apple Books purchases with Family Sharing – Apple Support

How to create a new Apple ID – Apple Support

https://www.imore.com/how-set-up-family-sharing-iphone-ipad

Whoever has the new AppleID will need to sign-out of the currently shared AppleID - and then sign-in to iCloud with their new AppleID. Then you can manually prune the data that doesn’t belong - without fear of deleting data from the other AppleID account.

This happened my husband and i. But he NEVER used or should l say, logged in, with my apple id on his device!! I simply just shared what i thought was to be only my icloud+ STORAGE thru family sharing!!! But in doing that, some how all my passwords( keychain) are NOW on his device?? WHY???? I also share apple music, but my playlists ARE NOT on his device so why are my passwords?? Apple states that when sharing icloud+ you can choose or "manage" what i share! Well thats BS!