Lost the domain after the CONVERT CHILD DOMAIN

A global import from cpanel worked fine, I had several child domain.
Due to the existing feature, I attempted a convertion of one of them.
During the process, I have an error message
STRING INDICES MUST BE INTEGERS [404]

The back button don’t reverse the process
Worse, the domain is deleted of the panel
it’s no more listed as vhost in OLS …

Fortunately, the directory and static files are on the server

I attempted to recreate the domain as child, all was fine.
But the convert feature creates the same issue …

If you have some advices how to fix this, where are the logs of this operations, your help is welcome …