@Cayle Thanks for posting in our Q&A.
For this issue, please check the registry key "LockScreenImageURL" under HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\PersonalizationCSP is same as you configured in the intune's configuration profile and check the value of "LockScreenImageStatus".
Here is the value about "LockScreenImageStatus".
If everything is normal but it still doesn't work on windows 11 devices, it seems an issue. It is needed to solve it with windows 11 team. With Q&A limitation, it is suggested to create an online support ticket to get more help. Here is the support link:
https://docs.microsoft.com/en-us/mem/get-support
Thanks for your understanding.
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