Gallery pix do not appear in post

Just noticed that a site that uses the GeneratePress theme (as the parent of a child theme that I used to add some minor CSS changes) is not showing gallery images on the posts.

The post has the proper gallery shortcode [gallery ids="435,436,437,438,439,440,441,442,443,444,445,433,434"] . The images show up in the post editor as a gallery. But they don’t show up on the generated page.

Thanks.