@Chloe Hall Thanks for posting in our Q&A.
To clarify this issue, we appreciate your help to collect some information:
1.The image is not added in your post, if possible, please add this image again. Any specific error code or error message is ok.
2.Please check if you can see this device in intune portal and "Managed by" shows "intune". Here is the example:
If there is anything update, feel free to let us know and we will continue to discuss this issue.
If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.