DNS Challenge OVH - unable to generate a certificate for the domains / NS ns.ovh.net. returned SERVFAIL

I'm coming back, because I have to use DNS Challenge, I think so...
Because I want to secure some other ports like 32400 (plex) and I would like to do it with traefik.
I have opened another topics recently :

And from another people about it :

I think so, I have to use DNS challenge to do what I want to do.

Are you sure it's not a "bug" about traefik (bad request for example), because 22 days ago, I have tried with certbot, and I was able to add the entry to the DNS ?