I am using guide provided at https://openthread.io/guides/border-router to create border router. I am using Ubuntu 18.04 on a PC. I tried same on RPi 4 too and seeing same issue. I am seeing problem after installation of ot-br-posix. I run sudo ot-ctl state command I get message "OpenThread daemon is not running". I checked log otbr-agent service and found that it keeps restarting due to some failure. Following is the status:
I am using nRF USB port besides RESET button and nRF power source button is set to USB. So configuration and hardware connection seems perfect as per the guide. I am using master branch of ot-br-posix repo and using master branch of openthread repo to build NCP firmware for nrf52840.
Please let me know what's going wrong here and how can I make border router work.