How fast are they flashing? It probably has something to do with the power supply that drives the LEDs.
LEDs are different from traditional bulbs in many ways, some of which can be a challenge in automotive applications. Most notably, LEDs can turn on and off instantly. If you shut off a traditional (incandescent) bulb you will see it get dimmer, quickly, but not instantly, and go out. An LED will go out immediately.
Since the alternators on our vehicles don't provide a constant, steady output voltage an LED running directly off the alternator would flicker. There needs to be some circuitry in line to smooth out the power (possibly just a capacitor) as well as to take the voltage down in most cases as LEDs often run under 2v, the automotive 12-14v would burn them out quickly.
It's probably something to do with that circuitry. It could be in the light controller or even part of the light module. Please report back once the dealer handles it for our education.
I know that doesn't help you actually fix it, but hopefully makes some sense. The dealer should be able to troubleshoot quickly. Thankfully LEDs are common on vehicles now, so troubleshooting should be easy.
