Matek H743 Wing often stuck in bootloader

Most of the time when I power on the device, I won’t boot. The USB based serial port wont come available and the red + the blue FC status LEDs are permanently on. This happens both through powering by battery (and the integrated BEC) as well as when powering over USB. Sometimes the boot continues after several minutes resulting in a working FC, however on other occasions when I left it in this state I did not get any change after hours. Sometimes the FC boots up just fine in a ~40 seconds (of which only for a few seconds both red and blue are statically on). I’m running arduplane 4.0.8, and I flashed the hex file with BL directly via the stm32cubeprog tool, as DFU flash is currently broken on several H7 boards.

Entering the (unfortunately bottomline useless) DFU mode works 100%, every time I power up with the boot button pressed it boots up and registers as DFU device if a computer is attached. How can I debug this issue further?

I did observe this behavior without any hardware attached. I do not use an sdcard.

I guess you should try ArduPlane 4.0.9 …