Hello @Loh Wai Kit ,
Thank you for reaching out.
A long Gap might have caused the issue Preventing the device from receiveing the new Update but I reccomend that you look at the Troubleshooting guide to really understand what might have happened. https://free.blessedness.top/en-us/troubleshoot/mem/intune/device-protection/troubleshoot-update-rings
From what I know, while Windows 10 devices running versions 21H1 and 1909 meet the version threshold (≥1607) https://free.blessedness.top/en-us/intune/intune-service/protect/windows-10-update-rings#prerequisites, they are no longer supported by Microsoft.
Once a version is out of support, Microsoft no longer provides feature or quality updates for it even if it technically meets the version requirement. As a result, I think Intune Update Rings will not deliver updates to these versions unless they are first upgraded to a supported version.
Make the devices with latest OS version, you can consider configuring the Feature update policy to select a latest OS version to upgrade.
https://free.blessedness.top/en-us/mem/intune/protect/windows-10-feature-updates
I hope this answers your question.
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