Meta not created by the plugin

Hello,
Since yesterday, and simply after modifying the ‘prefix’ parameter and resetting the invoice number, the plugin no longer works, no meta is created in the database (wp_postmeta table). Also I have found that the option to reset the counter, just after the type choice (sequential number), systematically crosses itself, without my asking … where could it be coming from and what should I do? Thank you

Hervé

Version : 3.1.4