Regarding your comment, “I assumed that the devices that were already with the Standard account would also show in the Premium.” could you please clarify which management portal or device list you expected the devices to appear in?
For example, were the devices already registered with Microsoft Entra ID while you were using Microsoft 365 Business Standard, and did you expect them to automatically appear in the Microsoft Intune admin center after upgrading to Microsoft 365 Business Premium?
If so, please note that simply upgrading the license to Business Premium does not necessarily cause existing devices to be automatically enrolled in Intune.
Also, while you were using Business Standard, were you signing in to Windows using the Microsoft 365 account in question?
Please also check the Join type of the affected devices in the Microsoft Entra admin center and confirm whether they are shown as Microsoft Entra joined or Microsoft Entra registered.
For Microsoft Entra joined devices, when the user has the appropriate Business Premium license and is included in the Intune MDM user scope, joining the device to Microsoft Entra ID can also trigger automatic enrollment into Intune.
However, if the device had already been joined to or registered with Microsoft Entra ID while the user was still licensed with Business Standard, simply upgrading the user's license to Business Premium may not automatically enroll the existing device into Intune.
Therefore, could you please check and share the following information?
- Which management portal or device list you mean by “appear in Premium”
- The Join type of the affected device in the Microsoft Entra admin center
- Whether Microsoft 365 Business Premium is assigned to the affected user
- Whether the affected user is included in the Intune MDM user scope
- Whether the affected device is currently displayed under Devices in the Microsoft Intune admin center
If you can check and share the information above, it should make it easier for others to provide you with more specific guidance.