Noticed that old EC2s which are in OFF state are appear in the AWS extension.
There are only 24 EC2s available (per the resource count metrics) but we see more than that and list increases with time.
Release : SAAS
Component : DX SaaS Agent 20.9
The Agent Sends Only the Active EC2 Instance Metrics to EM, but these changes are from 21.1 agent onwards, as the customer is using 20.9 Version of agent, these changes weren't there
DX SaaS Agent 21.1 or above is required