Custom Post Type Missing

This has never happened before with the Custom Sidebars plugin. I have a new site I am working on and when I go to assign a widget area to a specific post type, one of my Custom Post Types does not appear on the list. The Taxonomy for the post type appears when I select the option to show it in the Screen Options, but the post type itself does not show. It has a unique slug that shouldn’t be interfering with anything else and it shows up fine in other plugins like Yoast SEO. Just wondering if there is something I’m not realizing, that would possibly omit the post type from the list.

A few things I did try already were disabling and re-enabling my plugin that registers the post type. Flushing the permalinks. Disabling and re-enabling the Custom sidebars plugin. Setting the priority of the CPT registration to a lower value. None of these seemed to resolve it. Is there something else I should try? I’ve never had this happen before. WordPress and all plugins are up-to-date.

Thanks,
Wil