EC25E Mini PCie Module not responding some times when enter command thru Serial Port while SIM Card is inserted

We are using EC25E module, module is not responding some times while SIM Card is inserted.

We are using Ubuntu 20.04 OS. along with airtel SIM.
EC25E Module Info for reference
image

OS info

Can anyone help me out. one of Quectel engineer not able to solve this.

Thanks