Can't set secondary domain to be primary domain in Zoho sites

Can't set secondary domain to be primary domain in Zoho sites

I'm having trouble when I try to change my secondary domain (which is a sub domain actually) www.unggulgroup.com to be the primary domain of my Zoho sites. I've added the A record which point to  74.201.154.208 and  the CNAME mapped to  zhs.zohosites.com but still, it says that my domain is not configured yet. Though I can access my site using both unggulgroup.com or www.unggulgroup.com, I still want to change my "www" subdomain as the primary address of my site. Can anyone help? Thanks.