@Opeyemi Enitan, Thanks for posting in Q&A.
To clarify this issue, please check the following.
1.What kind of enrollment method do you use and what kind of policy do you apply to device? And share the details of policy.
2.Check if there exist GPO in target devices that may block UAC prompt.
3.Un-enroll the device from Intune and check whether the UAC prompt successfully.
Please check above information, if there is any update, feel free to let me know.
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