Workflow Automatic activity doesn't finish after resume

Question

We have a automatic activity in our workflow which we set to suspended(when we send the bundle items for translation), Once we get back the translation, we resume the activity.

The activity status looks like below:

In Suspend state:

After Resume:

Now after the activity resumed, It keeps on in the state 'Started' and never finish automatically. So we have to finish it manually every time.

We have implemented the resume method for the activity as below, but the control never reaches to this method where the activity is finished by code.

Is there anything obvious I am missing?

UPDATE:

I've created a simple POC pasting the same code from SDL Documentation as below:

 public class TestAutomaticActivity : ExternalActivity
    {
        protected override void Resume(string bookmark)
        {
            CoreServiceClient.FinishActivity(ActivityInstance.Id, new ActivityFinishData(), null);
        }
        protected override void Execute()
        {
            CoreServiceClient.SuspendActivity(ActivityInstance.Id, "Reason", DateTime.Now.AddMinutes(1), "ResumeBookmark", null);
        }
    }

Now It suspends the activity but never resume it (as per code it should resume after one minute).

Answer 1

By Default, the Tridion Content Manager Workflow Agent window Service runs under Local System account, But in my case it was running under some other user account (which was set in "This account" section shownin the image below).

Changing it back to Local System Account fix the issue.