You have set up different user accounts on your mobile devices.
Use the same user account to log in on all mobile devices.

The Miele appliances are not shown in the Miele app.
Use the same user account to log in on all mobile devices.
Uninstall the Miele app.
Reinstall the Miele app from the Google Play Store or Apple App Store.
Log in again on the Miele app with your login details.
Log out of the Miele app (Profile > Profile settings > Log out).
Log in again on the Miele app with your login details.
Reset the network settings on your domestic appliance (see operating instructions for the domestic appliance).
Re-network (pair) your Miele domestic appliance.