@Max2307 Just a heads up. Confirmed. This is a bug. When the "Rudder Controls Differential Brakes" option is enabled in DC-3 Settings, the code overwrites the toe brake axis values every frame, even when the rudder is centered. That zeroes out any input from your brake pedals, which is why the axes appear completely dead while button-bound commands still work.
As a workaround until the update: Open DC-3 Settings, go to the Options tab, and uncheck "Rudder Controls Differential Brakes." Your toe brake pedals should work normally after that. You'll lose the rudder-to-brake taxi assist, but you'll have full differential braking through your hardware.
The fix is already in for the next release. The differential braking option will no longer interfere with toe brake axes. When the rudder is centered, your pedal input passes through untouched, and when the rudder is deflected, the two inputs are blended rather than one replacing the other.