Occasional nonstop gas to electric to gas switching

When this happens, is your battery in the Energy screen all green? I have a long hill I come down on the way to my house. Frequently the battery goes solid green by the time I get to the bottom, so, to protect the battery from too high a charge, the car cycles the ICE on and off, without fuel, just spinning it up fast, to burn excess charge. Startling the first time it happened.

 

Mine never goes back and forth, but will occasionally either keep the ICE running (for no apparent reason), or keeps the electric motor running (mashing the brakes harder stops that one). I figure that the car knows what it is doing...although both felt strange at first.

If it is not what Bill or I have described the it would be a good idea to keep a log of the issue (time of day, weather, number of bars, route, how long you had been driving) to build a "story" for the dealer to then try to recreate.