I am seeing this issue on two production sites. One is using code that was the inspiration for our Jetpack_Compat class and the other is using this plugin.
This has been resolved. The problem was with filters on jetpack_sitemap_image_skip_post after the ones in this plugin. They were not honoring the decision made in previous filter functions.
I am seeing this issue on two production sites. One is using code that was the inspiration for our Jetpack_Compat class and the other is using this plugin.