This could be a number of different things but let's start with the basics first to see which path we may need to go down.
Let's check the transmission fluid. Unfortunately, this is not the easiest transmission to do that on. There is no dipstick so you have to remove the center plug from the drain plug on the pan and install a tool to drain and fill. I attached the procedure.
Also, we need to scan it for codes. If you don't have a scan tool then most parts stores can do this for you.
If the fluid is okay and there are no codes, and the vehicle is driving fine, then I would just leave it be until it starts to present a more consistent issue. I am not suggesting what happened is okay but I would hate for you to go make a repair if it never happens again. If you don't do a repair and it never happens again then you saved the time and money. If it does it again, then we will hopefully have more to go on.
Let me know what you find and we can go from there. Thanks
Images (Click to enlarge)
Monday, September 2nd, 2019 AT 6:10 PM