Are you sharing an AppleID? Sharing an AppleID between users is a very bad idea.
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 data stored in Contacts, Calendar, Messages, Photos etc.). 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).
As a first step, check that each of your devices are signed-in with the correct User's AppleID:
Settings > [Your Name / AppleID]