Phonebook search not working from homescreen

HI,
I have above mentioned mobile handset. In this mobile from home-screen if I press any name character then it's showing me a Phonebook search. Which is perfect.

But When I am trying to type any Number it's not searching names of my phonebook.
If I am pressing "0-Zero" on my home screen it's showing me all the names starting with "0", but once I press any other digit it's not showing any names starting with these two numbers.

Steps to reproduce:
1. Keep your mobile on home screen mode.
2. press any non-digit character.
Expected: You can find names starting with this character
3. now again come to home screen mode.
4. type any digit on your mobile.
Assumption: you are typing first digit of some pre installed phone book entry.
Expected: Names will be appear on screen starting with entered digit.
Actual: Names are appeared on screen starting with this digit.
5. Enter one onther digit on your mobile.
Assumption: you are typing second digit of some pre installed phone book entry.
Expected: Names will be appear on screen which are starting with entered digits.
Actual: Names are disappeared from screen and screen is blanked with only two digits.

Please reply if you are not able to reproduce this issue.
At my end every time this issue can be reproduced.

Regards,
Kaustubh Pagedar