Welcome to Microsoft Q&A Forum!
Thank you for providing the detailed information and observations.
Based on your clarification and description, given these findings, the issue does not appear to be related to client reporting, update deployment, or a normal data refresh delay. Instead, the behavior suggests a possible discrepancy between the data used by the Update deployment status views and the data used by the Security update status and Latest security update summary widgets.
The Latest security update tile should reflect devices that have successfully installed the most recent security update, while the Quality Updates and Summary views are intended to present compliance information derived from the reporting data. Therefore, a mismatch between these views may indicate a service-side reporting or classification issue
At this point, I recommend you opening a Microsoft support request so that the Windows Update for Business Reports team can review the underlying reporting data and determine whether there is an issue affecting the compliance calculations or dashboard presentation.
For support options and guidance, see: Windows Update for Business Reports - Feedback, support, and troubleshooting [Feedback,...soft Learn | Learn.Microsoft.com]
For additional information, please visit: Frequently Asked Questions (FAQ) - Windows Update for Business reports | Microsoft Learn
Use the workbook for Windows Update for Business reports - Windows Update for Business reports | Microsoft Learn
I hope this helps clarify the issue, and thank you for bringing your concern to Microsoft Q&A.