Identify and remove ghost SCOM Agents

Hi,

In my SCOM environment, I found few SCOM agents that do not exist now and removed from 'Agent Managed' section from Administration workspace. Still I find issues below:

1. Some SCOM agents are still visible on Monitoring workspace on path 'Monitoring --> Operations Manager -->Agent Details --> Agent Health State'.

2. While other SCOM agents are still visible during fetching Reports while Adding Groups/Objects into the report.

Please help me with a way to remove these ghost agents from both of these aforementioned views. These agents are not present in the environment an generate fake alerts/reports.

Thanks & Regards,

Suraj