My iPhone won't sync my contacts or messages with my MacBook Air, instead it syncs with my sisters phone (her iPhone used to connected to my Apple ID) and idk how to fix it. The only thing it syncs correctly is my photos.
MacBook Air
For Contacts, try going to iCloud.com using a computer to see if the items are there and whether they are from the device or the computer. That should show whether the device or the computer isn't syncing. If the computer, try going to System Preferences/iCloud and stop syncing. Wait a couple of minutes, then recheck syncing. If the device, go to Settings/Your Name/iCloud and do the above. As a last resort, you can also try signing out of iCloud and then sign in again.
If your sister's phone sign into Settings/Your Name/iCloud using your Apple ID?
For Contacts, try going to iCloud.com using a computer to see if the items are there and whether they are from the device or the computer. That should show whether the device or the computer isn't syncing. If the computer, try going to System Preferences/iCloud and stop syncing. Wait a couple of minutes, then recheck syncing. If the device, go to Settings/Your Name/iCloud and do the above. As a last resort, you can also try signing out of iCloud and then sign in again.
If your sister's phone sign into Settings/Your Name/iCloud using your Apple ID?
iPhone won't sync correctly with MacBook Air
