Hi,
I would recommend doing 2 things:
- Run the Server cleanup Wizard
https://learn.microsoft.com/en-us/windows-server/administration/windows-server-update-services/manage/the-server-cleanup-wizard - Reindex the WSUS datase:
https://learn.microsoft.com/en-us/troubleshoot/mem/configmgr/reindex-the-wsus-database
Please let me know if my solution worked for you.