Subdomains in Cpanel V108

Hi, I have a problem in Cpanel V108, i created a cpanel account with a domain, now in cpanel V108 de subdomain must be created in domain section, only is neccesary agregate the prefix and this is all. But in my cas i created the subdomain and my subdomain don't work. - I have my DNS server good configurated - My principal domain working fine - I agregate en DNS Zone from my principal domain de subdomain name and the IP server. But nothing work and i dont know why. In others post read any relationated with firewall and the port but in the first time that read some as this. Because in cpanel is very easy create subdomains.