I have a running jenkins version 2.414.3 and having installed Amazon EC2 plugin version 2.0.7. I have tried changing multiple Idle termination time for EC2 like 2 min to 30 min still it is not getting terminated but it is getting stop/disconnect when I select the checkbox for Stop/Disconnect on Idle Timeout it is working perfectly fine. I have attached the role as per instructed in the https://plugins.jenkins.io/ec2/

I have attached the screenshot of the configuration done by me.
NOTE: AMI Type is Unix