Zoho Works Well on Browser but not on Mobile

Zoho Works Well on Browser but not on Mobile

Have migrated Google app emails from 2013-2017 to Zoho successfully but when i try setting up my iPhone to retrieve emails following these instructions ->  https://www.zoho.com/mail/help/idevice-access.html  

I can sent emails successfully but get an error as below when trying to receive emails.  Anyone know how to remedy this issue? 

Thanks,
Diego