Try to edit the file themes/tethys/woocommerce/loop/loop-start.php and replace the following code
<div id="main_loop" class="xts-products<?php echo esc_attr( $wrapper_classes ); ?>" data-source="main_loop" data-paged="1" data-animation-delay="<?php echo esc_attr( $animation_delay ); ?>">
with this one
<div id="main_loop" class="xts-products products<?php echo esc_attr( $wrapper_classes ); ?>" data-source="main_loop" data-paged="1" data-animation-delay="<?php echo esc_attr( $animation_delay ); ?>">
We will also fix it in our next theme update.