DRV8830 motor controller -- drive is working but brake is not
Can you measure the OUT1 and OUT2 voltages if possible? In both when enabled to run and when brakes are applied. Also, are nothing reverse and forward commands working fine?

Simple steps to make sure the commands are being transmitted or the bits are being interpreted properly.

Reverse and forward commands make sure that both bits are being addressed.

Brake should work.

If the motor is not stopping soon, I would do the following. If it is running in forward direction, I enable it to run in reverse direction for short moment and then apply brakes.. This brings motor into halt state faster.