No. We don't know why it is so because you did not shared any information around it.
Though, have a look at
this similar thread[
^] which suggests adding:
<add name='Reserved-ReportViewerWebControl-axd' path='Reserved.ReportViewerWebControl.axd' verb='*' type='Microsoft.Reporting.WebForms.HttpHandler' resourceType='Unspecified' preCondition='integratedMode' />