I had my rotors and pads (ceramic) changed last spring. They are fine most of the time. quiet, dustless, etc...

Recently, I've noticed that if I do a lot of stop-and-go in traffic, or if I push the brakes to force the car to stop hard at the end of the braking path (usually at very low speed, about to stop, 2-3 km/h max), the front brakes will start grinding after that, everytime I'm about to stop, when it drops below 5 km/h, no matter what kind of pressure I put on the pedal.

sounds like fork-in-a-plate/metal-to-metal-oh-my-god-my-pads-are-completely-finished grinding.

Doesn't sound like the ABS (which sounds more like a percussion drill)

I park it, and a couple hours later, it's gone.

does not happen at high speed. even when I'm slowing down, nothing, until I reach the last 30 feet of braking.

Any ideas?