Approx. 10 to 15 times, at least, since 2010, approx. once a year or more when using the brakes, usually, but not always the first time after starting out somewhere the abs stability control activates with the pedal bouncing as you continue to push down on the brake pedal and vehicle does not want to stop, maybe twice the distance to stop. Stops very slowly, you can stand on the break pedal, try to pump it, you can stomp on it but it continues pulsing severly and usually making a grinding noise, from the abs? Always continues for many attempted stops, sometimes will not go away for up to 60 minutes or so or until it is parked and left alone for a day. Was serviced by Ford dealers until 100K, never fixed.
Ask your shop if there’s a way to temporarily disable the ABS system, and if so have them show it to you. Then next time this happens you can disable ABS and see if that return the brakes back to normal. If you ABS is triggered by the wheel speed sensors makes sense to verify each of them are working correctly, as well.