Hi there, so if you are trying to update to the latest feature update version via Intune there are a few reasons this may not be working: 

1. Policy conflict (make sure you have no leftover policies from Configuration Manager, Group Policy, etc. that could be causing conflict)
2. Safeguard holds Safeguard holds for Windows | Microsoft Learn which should go away automatically 
3. If moving from Windows 10 to Windows11, in addition to the deferrals, you will need to select target product version = 11, you can do this via the "Windows 11" toggle on the rings page or via Settings Catalog. 

Hope this helps, let me know if you have any additional questions! :)