Working alert with the group by functionality

Summary:

Dear all

We have a requirement to send single alert to line manager who has multiple reportee end dated on same day.Reportees should be come in table format in email .i.e for each reportee new row in table .but the issue is in email , employees with same end date are coming in one row comma separated.
Expectation:

We are getting like below:

Version (include the version you are using, if applicable):

Code Snippet (add any code snippets that support your topic, if applicable):

Group by : ${AlertUtils.empManager(workers.PersonId).PersonId}

Source Code :

Could you please let know what is going wrong here ?