PNG/JPG conversion not working in WP-Smush with Amazon S3

With WP Offload S3 Lite active, the PNG to JPG conversion option in WP-Smush Pro does not work well. Images are indeed converted to JPG, but are not offloaded to S3, have no Smush data at all, and appear broken in the media library. However, they are accessible at their File URL.

When the PNG to JPG conversion option is disabled, PNG images are uploaded, smushed & offloaded to S3 successfully.