Are you sure its not the hill assist? The brakes will hold you on a hill to keep you from rolling back until enough acceleration is applied then it releases. Mine is not always consistent, sometimes it holds it harder than others.
When you let off the brakes after coming to a complete stop the vehicle keeps the brakes engaged until you apply enough gas to break it loose. I find that mine is inconsistent sometimes and i will need more gas than other times to overcome the brakes.It could be, I don’t know what “activates” to keep the vehicle from rolling back. After topping off the oil, I tried to replicate it but it acted fine