Find the bug! Needs fixing. Not tuned! And something crashes the board.
When vibrating a lot (probably high gains or high d-term / d-term noise) or when the robot leans a lot to one side everything freezes. Both loops blinking leds stop completely and steppers stay at last command.
I've tried electronic fixes and lastly put the controller on its own power supply.
Can be triggered even without any power electronics connected (rocking the robot by hand). So it seems to be software related!