BG-95 M3 UART not responding

I have designed custom PCB for BG95 M3 board. I control the board through AT commands from a microcontroller through UART. I have ordered 5 prototypes and tested it works. Recently, I made another purchase for 5 other prototypes and these do not respond to UART. They also do not respond to USB commands unless DTR option is ticked.

On UART port, I get the RDY and APP RDY messages.

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The firmware version is BG95M3LAR02A03_01.200.01.200 .

Could anyone please help me solve my issue? Can I disable DTR? Is it related to firmware version?

Discuss with email already!