Coordinator API and End nodes AT mode...

I am working with coordinator (API) on latest 208C firmware and other end nodes are working on 288C firmware.

My problem is that when I was using 2x70 firmware on both side it was working fine. but when I am uploaded new firmware my coordinator is receiving packet in parts…

but if I change firmware on the end node back to 2870 and leave the coordinator to new 208C, again both works fine.

I want some one to check if they have same problem …??
I guess end node 288C firmware is not tested properly