To get personalised results on your Assistant-enabled device, you must be signed in to the same Google Account that is linked to the device.
Check which Google Account is linked to a device in the Google Home app
- Open the Google Home app
.
- Tap Favourites
or Devices
..
- Tap and hold your device's tile.
- Tap Settings
Recognition and sharing.
- Tap Linked account(s) to find the Google Account(s) linked to this specific device.
.
or Devices 
..
Recognition and sharing.