A few month back, there was an update to the heart in the Match players bar widget and it probably hasnt been updated in the skin you're using
if you use the search, you should be able to find several posts about it
replace the current code with this and it should be updating correctly again
<widget class="player_condition_icon_widget" icon_alignment="centre" width="16" navigation_focus_target="false" id="PcOI" label_disabled="true" show_hover_popup="false"/>
widgets/match players bar widget.xml