Hi there,
That’s strange – can you try adding this CSS to your site to test?:
.wp-show-posts-columns .wp-show-posts-single:not(.wp-show-posts-masonry-block) {
display: -webkit-box;
display: -ms-flexbox;
display: flex;
-webkit-box-orient: horizontal;
-webkit-box-direction: normal;
-ms-flex-direction: row;
flex-direction: row;
}