BC68 NBIOT modem with Cortex M0 MCU

We have been using BC68 with Cortex M0 MCU. MCU uses Low power UART to interface with BC68 with 9600Baud rate. Initially interface worked without any issues but over the time, we started getting frame errors which is CME ERROR 523, 530. Any advise on this.

Hi Yogeshk
AT+NATSPEED=9600,30,1,0,2 //Change sync_mode parameter
UART Port Baud Rate bandrate already exceed the error range.