When I manually disable all plugins except Yoast SEO and set a default theme the post-sitemap has an error.
When I use the Health Check & Troubleshooting plugin with Troubleshooting Mode – enabled the post-sitemap works.
The troubleshooting mode disables all plugins and activates a default theme. But without using the plugin and I do the same thing (disable all plugins and activates a default theme) the post-sitemap has an error.
To begin with, you could pull it from the title of the post. Then you could add options to use the excerpt of a post, the tag, or the category of the post.
