DIAGNOSIS This is normal behavior, not a fault. These washers (and most modern ones) have sensors that constantly check for suds and soil levels. If it detects more soap or dirt than expected, it automatically adds extra rinse and tumble time to ensure clothes are clean.
FIX To get times closer to the display estimate, use the minimum effective amount of HE detergent. Overdetergenting is the biggest culprit. Also, make sure you're selecting the right cycle for the load size and soil level—using "Heavy Duty" for a lightly soiled load will add time.
IF THAT DIDN'T WORK If the cycle seems to hang indefinitely at one point (like "Rinsing"), it could be a drain issue. Check the drain hose for kinks and the drain pump filter for a clog, as a slow drain will dramatically extend cycle times.
HEADS UP The displayed time is always just an estimate based on a perfect, average load. Don't rely on it for precise scheduling. If you need a guaranteed time, use the "Timed Wash" cycle, which runs for exactly the duration you set.