The Device ID should be unique enough to exclusively identify a device/client and shouldn't get lost if the app updates.
=== Windows ===
For UWP / XAMARIN UWP:
In the UWP/WinX client, the device id is created using the [https://docs.microsoft.com/en-us/uwp/api/windows.system.profile.hardwareidentification.getpackagespecifictoken ASHWID identifier] encoded to a Base64 string. (<= 3.7.X)