Zoho Mail on custom gTLD domain

Zoho Mail on custom gTLD domain

Hi,

I'm trying to register a Zoho Mail account with a custom .family domain that I own, however I'm having troubles with the signup form, as it looks to not support custom gTLDs like .family.
When I fill all the fields correctly and hit the signup button, all I get is a red bar indicating that an error occurred.
When I entered a regular domain (e.g. ending with .fr), everything seemed to work fine and a new account was created.

Now, in this newly created Zoho Mail account, when I try to update the DNS name of my domain with [xxx].family, I also get an error, stating that This Operation has been restricted. Please contact support-as@zohocorp.com for further details.

Any statement on this? Are custom gTLD domains supported or not?

Kind regards,
Romain