Since it happens when you apply the brakes, it is likely related with the brake system. It is likely the brake fluid level is a bit low.This might also happen when you drive the car in slope and apply the brakes.When the car is back on leveled road, the fluid level is just high enough and the floater does not trigger the brake indicator in the combination meter.
Check the fluid level; if below MAX, add it to MAX.
Hope can help you. Without inspection, however, it is hard to pinpoint the problem.