DIAGNOSIS The backup capacitor on the main control board has failed. This capacitor holds a small charge to keep the clock memory alive during brief power interruptions. When it dies, the unit loses all programmed settings instantly.
FIX There is no user fix for this. The surface-mount capacitor on the control board needs to be desoldered and replaced with an identical component. This requires electronic repair skills and access to the main board.
IF THAT DIDN'T WORK The entire control board may have other failed components, but the clock reset symptom in isolation points directly to the backup power circuit, specifically that capacitor.
HEADS UP The brewing functions will still work. This is purely a memory/clock issue. You can use brew button without setting the clock. Do not attempt to open the sealed base unless you are qualified—line voltage is present.