2015 Lincoln Navigator POWER TRAIN,ELECTRICAL SYSTEM,SERVICE BRAKES

When in park, vehicle fails to stay parked in some instances. For example, SUV has rolled forward (while in park): when parking on an incline or while unloading items from trunk, resting against bumper caused it to roll ahead and hit closed garage door in the garage, or when leaning on the SUV body outside vehicle it can disengage from park and start moving while shifter stays in P position. Emergency break stops movement. We started noticing the issue Jan 2022 and took it to Lincoln for service on 02/25/22 to investigate (after multiple accounts, same concern). They found no recognizable problem, stating vehicle might not have been in park to begin with. No parts were removed; only a visual & functional assessment. Paid an inspection bill with no resolution to safety concern. However, it re-occurred on 4/2/22. Because the concern is intermittent and cannot be replicated on demand it’s harder to predict when SUV will move. Using the emergency parking break as a safety back-up for now. Vehicle is available for further inspection. To date, no major damage caused. Yet, forgetting the manual break could result in a terrible situation at any time. All instances of rolling away have occurred after driver exited the vehicle. Level parking surfaces are not always available. Probably unrelated to the safety issue, there are strange electric bugs. Radio will turn on randomly while driving; tailgate will open on its own when SUV is parked. However, no warning messages have displayed for any of the safety or electrical issues described.