Badger 2040W + Custom U2F + Bluetooth + Battery Issues

I’ve recently got a Badger 2040W, and wrote a small C++ program that spins up the Bluetooth LE radio and draws images to the screen. On USB, this works perfectly fine. However, when I connect the battery power that comes w/ the Badger 2040W accessory kit, the application fails to start. I’ve seen some discussion about how to “restart” the chip by holding reset and a front button, but I’ve kinda assumed that is a thing programmed into the MicroPython / “Badger OS” U2F that is no loner present, as I’ve replaced it with my own program.

Is there a trick or special behavior I need to add to my C++ code to get the application to start on battery? Or some other consideration I should have? ( Note: I’ve tested my batteries, they do have power. )