I'm unable to finalize the domain verification process to set up my email address

I'm unable to finalize the domain verification process to set up my email address

Hi,
I did everything and then according to the instructions:  You have now added the CNAME successfully. You may have to wait for at least an hour for the changes to take effect in the DNS Servers. After an hour or two, log in to your Zoho Mail Control Panel and click Verify.
If I click Verify it brings me back to the beginning of the verification process which I already did. this is very frustrating. Can you please let me know how to finish the process?
Regards