Unable to update POD

Hi,

I have a simple POD custom type, whose slug is ‘npsau_set_apl_res_pe’, using all 20 characters available by WordPress. Within it, I just have a custom field of type “Plain Paragraph Text”.
When I try to save it, without making any changes, I get the message “Error: Pod npsau_set_apl_res_pe already exists”. The same happens when I try to save it with minor changes or when I try to change the slug, in which case, the error message reflect the name to which I’m trying to change the slug.
I have 15 other PODs custom types, and any of them give me that error while saving with/out making any changes.

I didn’t find any clue on debug.log.

Thanks for any tip you can give me!