We're using the "nRF connect SDk" to install BLE mesh on the BL653 development kit,and we're using the same configurations as they provided. As per this, the NRF mesh application is able to detect the bluetooth module from the board(BL653 development kit) after flashing the code into it. However, it is unable to locate the Bluetooth module.
note- We used Segger embedded studio with the nRF Connect SDK, and we double-checked the board selection and SDK application.
Link - infocenter.nordicsemi.com/index.jsp