"Health" APP using wrong iPhone for input

TBS2,

Yes, that is correct. However, it may be worth reviewing this resource and the information below: Make sure that each family member has a unique Apple ID

"Avoid sharing an Apple ID

Apple recommends that you do not share your Apple ID. Instead, set up Family Sharing so that each person uses their own Apple ID. This way, your family can share purchases, subscriptions, and more without sharing personal information like email, text messages, or passwords.

If you share your Apple ID with a family member, certain services will treat you as the same person. You might see these issues:

• Apple Music family subscription: Instead of receiving your own membership with your own library, you’ll share a library and recommendations with the other family member.
• App Store, Apple Books, and iTunes purchases: If Family Sharing is ever stopped, the owner of the shared Apple ID will keep all purchases. You might lose access to everything in the account, including purchases you initiated.
• Apple Podcasts, Apple Books: Podcast episodes and bookmarks might sync according to the other family member’s preferences or be accidentally deleted.
• Messages: You might receive text messages that are intended for your family member."

Best wishes.

Hi TBS2,

​Thank you for using the Apple Support Communities. If we understand correctly, it sounds like some Health and activity data is syncing between two iOS devices and you're sharing an Apple ID. Is that right?

Generally speaking, it's recommended to Make sure that each family member has a unique Apple ID. In this case, it sounds like you might have Health syncing turned on under Settings > [name] > iCloud. Is that turned on? Back up your Health data on iPhone

If that doesn't seem to account for it, we recommend contacting Apple with this link: Get Support

Take care.

TBS2,

With Family Sharing, the Contacts and Photos are kept separate. However, you can use a shared photo album if you did want to share some of the photos between the two Apple IDs.

Kind regards.