Missing “WordPress Post Formats” in the list? or Post Formats not working correctly?
Most probably It might happen after you upgrade your WordPress version. Because some themes still not supporting to the Last version of Gutenberg editor plugin, the most easiest way to overcome this issue is to switch the default editor with the WordPress Classic Editor plugin.
Or
Mortify the theme support;
add_theme_support( ‘post-formats’, array( ‘aside’ ) );
add_post_type_support( ‘post’, ‘post-formats’ );
