I have a problem since I've updated to WP 6.4.
I can't preview custom post type anymore, when I click on the preview button in my post I'm redirected to wp-admin/undefined.
I've disabled plugins and Metabox seems be the origin of the problem and more specific on the relashionship part. I've disabled this specific componant and it's working. The problem is I need relationship.
I suceedeed to reprocuce the problem on a new website even where there whas no relashionship set but the componant was active.