Zoho Mail App (Android version on Blackberry Passport) not working

Zoho Mail App (Android version on Blackberry Passport) not working

OKAY my native language is not english, I hope you get me right.

THIS IS A BUG DESCRIPTION

If you install Zoho Email on a Blackberry Passport running BB OS 10.3.x.xxxx, the actual version of the Blackberry Software, The App do not show the Emails.

I installed the App from the Amazon Repository, as a Android App.
BTW. starting with BB OS the phone is also able to run Android Apps

also BTW the CRM app works without problems.
Also The Email App shows the number of unread email correctly but it does not show the email in the list.
The list is empty.