System Workbench for STM32

Hello STM32 users,

I am a newbie to STM32 and I have an issue in the UART communication(STM32H779I eval board). Basically, I send data from the terminal application to STM32's UART, do some processing and respond back.
In my code, I receive data by HAL_Receive_IT and transmit normally(no interrupt). I keep sending commands from the terminal every 1 sec or so. After a while, STM32 stops responding to the sent commands. It works fine on power resetting the controller.
On checking, I find that the callback function for Receive interrupt itself is not called. I have checked for overrun/parity/frame/noise errors and none of these flags are set.

Can anyone please help me? Am I missing something here?

Any help would be appreciated

Thanks in advance,

Sapna