Hi @thucphuonga4, this is a community of cloudflare users, to reach Support, login & go to https://dash.cloudflare.com/?account=support and select get more help.
I see the change with a dig:
$ dig ns nhamaylien.com +short
But whois returns different results:
$ whois nhamaylien.com
Name Server: NS1.DIGIPOWERDNS.COM
Name Server: NS2.DIGIPOWERDNS.COM
Did you change your nameserver names with your hosting provider or with your domain registrar? If your registrar, you may want to contact them to see why there is an issue. If your host, that won’t help, you need to change them at your registrar.
Edit: Actually, that zone is on a partial partner setup where you don’t change nameservers. Only the partner with whom you added cloudflare can assist.