Exchange Active Sync issue - Xiaomi Redmi 4G Note or MIUI android 4.4.4

Dear All, 

We are in technical support for exchange active sync. We are getting number of calls from Redmi 4g note device users, as they are unable to configure or change their password in particular device model(Redmi 4g note, android version 4.4.4 Kitkat).

The same password is working well and good in Outlook, Webmail and other android/IOS devices. 

Steps taken as of now: 
User formatted the handset, flash the device and Hard/Factory reset,
Disabled the active sync service & enable again for users from exchange server, 
Removed accounts from webmail. 
We download some apps from play store and tried but no luck. 

While configure exchange active sync in Particular model users are getting error as "User name and password incorrect". 
There is no issue from exchange server and user account. as same is working fine in other devices. This issue happening for more that 10 users and receiving more calls day by day.

I request anybody to take it forward and provide the solution/suggestion, if it is a known bug for particular device model. Please confirm back. 

We are waiting for someone valuable reply. Many thanks in advance. 

- Senthilkumar.