Hi @Raphael, already checked those threads, only one guy having a similiar issue than me:
Thing is, i’m not using Cloudflare for my server domain, as i understood, error 400 is due to bad dns configuration, when i installed the HestiaCp, the panel didn’t added the DNS rules automatically like Vestacp, dns and mail are empty, should id add the rules manually for the domain and then try to SSL?