Unmanaged node receive multiple stop message after it shuts down

When using the unmanaged nodes. The service sends multiple stop messages after the node is shutdown. 
This causes new instances of the node to exit soon after launch

[AB#45531](https://fuzzfest.visualstudio.com/5eaacf23-2084-4d62-8fbe-7d37326a8b74/_workitems/edit/45531)