When SEL0 is tied to GND, the Debug TX goes low, so no debug prints are visible.
To resolve this, remove the jumper after powering on the board.
A boot mode switch can be provided to toggle the boot mode pin. Please refer to the carrier board schematics for details on the pull-up/down values and circuitry. (For carrier board schematics and pinouts details please connect with iWave representative.
For further inquiries, please get in touch with mktg@iwave-global.com
Please find the detailed G50M product information in the below link,