If you have multiple devices using the same Apple ID and you change your password the password needs to be updated in the main Apple ID system.
If you changed the password on one device but have not disconnected them from the internet or been prompted to sign in and did so on all devices the system is confused as you are signed in with the same Apple ID email with two different passwords.
Easy way sometimes is to either put other devices on airplane mode or turn all the devices off at same time and then on again and you should then be prompted to enter the new Apple ID password on the other devices. And the system should be updated.
Once this is complete sign into the Apple ID account page to verify all updated.
Manage and use your Apple ID
https://support.apple.com/en-us/HT203993
Hope this helps!
Joy