@Dave Thanks for posting in our Q&A.
Generally, intune Device ID is uniquely identifies the device. Different device IDs mean different devices.
To clarify this issue, we appreciate your help to collect some information:
1.Which enrollment did you use? Autopilot or co-management?
2.If it is autopilot enrollment, did you configure "apply device name template" in the autopilot deployment profile?
3.Could you please show the screen shots about these two records in Azure AD portal and intune portal?
If there is anything update, feel free to let us know.
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