CPTs disappear when edited

Hi Long - apologies for the confusion but I'm talking about native Metabox CPTs.

I create a CPT using Metabox and everything works normally, I can write posts using that CPT and everything is great.

However, if I later edit the CPT names (for example, perhaps I might want to change the chosen plural name so I edit it in Metabox and update). When I go back to the CPT in WP admin all the posts have disappeared. If I change the edit back then the CPT posts are returned.

I have tried re-saving permalinks but that doesn't solve the porblem.

Thanks so much Long - I knew there would be something logical to explain it. Makes perfect sense. Many thanks for your help.

Harry