contact group custom rule to fetch contacts who uniquely opened issue emails

I'm trying to get contacts who opened specific newsletter issue emails and using following code

WhereCondition whereissueId = new WhereCondition("OpenedEmailIssueID=" + issue.IssueNewsletterID);
var contacts = ContactInfoProvider.GetContacts().Source(sourceItem => sourceItem.Join("Newsletter_OpenedEmail", "OM_Contact.ContactEmail", "OpenedEmailEmail", whereissueId, JoinTypeEnum.Inner));

I can see total number of unique opens using issue.IssueOpenedEmails but what I need is these contacts email list who opened opened the emails.

But it's not matching the number of unique opens in email marketing report.

I just want to fetch the list of contacts Kentico shows in "Contacts who opened the email" in email marketing report.

Is there even any way to fetch unique opened emails list from "email report insights" using api?

Thanks in advance for any help