Why do RT activation list sometime shows multiple warm-started activations?

[sarav_prakash]

I am running a job on AppBuilder project. I created an action; set the web='no'; created trigger and rule, so every 5 mins action invokes successfully. 

I deployed the same action into 2 workspaces. I observe that one of workspace alone runs multiple activations, while other workspace runs correctly with single activation. Here is an example activation list.

Here there is cold start for every 5 mins. After cold start, always there are 3 warm starts. Any given instance, 3 activation pods are running. 

Impact is, same event is getting processed 3 times and sometimes resulting in errors. Is there a way to trash duplicate activations and keep it clean?