Participant information missing from free event thank you page

\templates\CRM\Event\Form\Registration\ThankYou.tpl page for free events doesn't include participant information but paid events do.

{include file="CRM/Event/Form/Registration/DisplayProfile.tpl"}

in
\templates\CRM\Event\Form\Registration\Confirm.tpl
display nothing for free events

{if $primaryParticipantProfile}

&&

{if $addParticipantProfile}

in
\templates\CRM/Event/Form/Registration/DisplayProfile.tpl
are empty