Hi Gurubaja. Please update information in your post - BT keyboard was working correctly on PB Pro 903 with older firmware. Now I have tested it with 2.1.3, with same result as you on 902 - only cursor keys and enter are working.
Sorry for confusion with 903 - I was not aware that something what was working in old firmware could/would be messed up in newer. (You know it in IT - never try to change something, what is working.)