@Rob Fletcher Thanks for posting in our Q&A.
For this issue, we appreciate your help to collect some information:
1.Which enrollment method did you use to enroll this android device?
2.Please check if there is any restriction in Devices > Enroll devices > Enrollment device platform restrictions in intune portal.
3.Please check if the target user has enrolled device is more than a limit on the number of devices a person can enroll. The device number limit is under Devices > Enroll devices > Enrollment device limit restrictions.
4.Please check if there is any enrollment failure message in Troubleshooting + support > Troubleshoot > select the target user > Enrollment failures.
If there is anything update, feel free to let us know.
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