When opening inline HTML reports as Evidences from the Test Run screen, it should show all Details of the Report

When having the setting called Internet Explorer MIME Sniffing Security Hole Workaround Policy from the JIRA ADMINISTRATION -> System -> General Configuration with the option Insecure: inline display of attachments selected, this will make all the attachments to be inline open automatically with a left mouse click.
If you open HTML Reports added as a Test Run Evidence this way, it will not show all the details from the HTML report. Although if you right-click and Save the file it will be downloaded and opened correctly.