RFD 868x Green lights on and Red lights blinking

Hello, i am experiencing an issue with two RFD 868x modules, and i cannot find information about it neither in the user manuals, FAQs, or on the web. I have one modem connected with the FTDI to USB cable at the PC, and the other is connected to an Arduino UNO with the RFD900 SHIELD V1.0. They have the same configuration, set independently with RFD900 Tools. When i supply power to both of them, the green light becomes immediately still and the red light starts blinking continuously and very fast. I want to transmit a simple message just to try the hardware, but i don’t think they communicate.

@A5tanA Hello, we have the same problem and I urgently need to solve it. If there is an improvement can you please help me?