Custom Post Type Post - Show in nav menus - not working

Hi there,

I tried to save permalinks over and over.. unfortunately without any luck. The Custom Post Types do not show up in the navigation menu settings.

Now I have tried to change the slug from singular to plural. Automatically Metbox will use the singular name.

So I have changed the slug from "boat" to "boats" and "tourist-info" to "tourist-infos" and "tour" to "tours".

AND you know what, know these show up in the navigation menu.

Now there is another problem though, all the custom post types posts (boat 1, boat 2, etc) are now gone. They don´t show up als posts under the "Boats" menu.

When I change the slug back to singular, the posts are there again... but now the custom post types don´t show up und navigation menu.

I wonder if anyone else has noticed this behaviour...?

Hi,

Thanks for your reply.

No, I did not create posts, pages or other CPT with similar slugs.

To be absolutely sure I´ve created a blank / fresh WP instal.
The standard Theme installed, NO other plugins installed but
- Metabox, Version 5.4.1
- Meta Box AIO, Version 1.13.13

Then I created a new Post Type:
- Plural name: Boats
- Singular name: Boat
- Slug: boat (automatically filled by Metabox)

Then I checked the Appearance, Menus > Add menu items.
No luck, only Pages, Posts, Custom Links, Categories are available.

Then I went back to the created Post Type > Boats and changed the slug from "boat" to "boats".

Checked the Appearance, Menus > Add menu items again... AND now the new Post Type (Boats) is shown!

I have made a screen recording, so you can see for yourself:
https://drive.google.com/file/d/1Xkny6VrE73d5Q1covLbsbO6BsFrmj7wg/view?usp=sharing

Thanks