ibewill

Hello. We bought a 2018 Black Label MKX. After three days the audio went out and nothing would change the volume. Let set for an hour started and it was working. Happened again 2 days later. Audion goes out suddenly volume shows 9 but will not change. So far it hasn't come back on yet. Did soft reset twice (Power & FF). Haven't done hard reset. Anyone have an idea? Need more info? Thanks, William