BC127 DISKIT from Digi-key not responding to Commands

I recently bought a BC127 DISKIT from Diki-key (Orange board ), However when i try to send commands to it using the serial terminal (Hercules) it ONLY responds to the first command i send and at times it never responds to the first command at all. It will just reply with error code 0x0012. During this time i will have connected my USB cable on the USB-UART port and the SW1 switches will be set to ON.

My second question is if i were to send commands using an Arduino, do i need to use a 3.3v level shifter on this DISKIT board?

Please kindly assist.