XCTU cannot send frames when connected to arduino?

hi, my coordinator is connected with XCTU and arduino and I’ve been using them both look at the frames it receives .

But when my Xbee is connected to TX and RX on the arduino, XCTU doesn’t seem to be able to send out frames and receive frame responses. When i remove the TX RX, XCTU can send and receive the responses. As my project requires arduino, I’d like to know why it is and how I can overcome it?

Check your Arduino code for sending and receiving mode. Your XBee is configured in which mode? AT or API

The coordinator is on API and the router is on AT. What should I be checking for my arduino code? Right now the code is just for receiving frames.

I’m trying to use XCTU to send AT Command frames and to see if Arduino can pick up the AT Response. But currently, when its connected to the arduino, I can’t get any response. When it is not connected, yes, from the XCTU terminal, i can see a response.

Can you please share your code?