Ok, it's a theme issue actually. The plugin is targeting a different set of classes so you might try changing the initialization code at q2amarket-user-hover-card/assets/js/uhc_script.js at to this:
// Original selector was '.qa-avatar-link, .qa-user-link'
$('.king-avatar-link, .king-user-link').tipso({
tooltipHover: true,
background: '',
width: 300,
useTitle: false,
position: 'top-right'
});