Featured sudden speed loss

that sounds like a defect. even in ev mode, prime should kick the engine in when you need more power

 

With the Prime it will still use electric at full acceleration in EV Mode unless you're going up a steep hill or already at highway speed and hit it or it's cold outside. In EV Auto it'll drive more like the PiP where it fires up the ICE to assist when asking for additional power. But during summer you can mash it down to the floor and it'll keep it in EV for the most part. But, if you're at full acceleration on the highway and still losing speed and the ICE isn't firing up then something ain't right with OP's car and they need to take it in to get looked at.

 

Once, I merged onto a crowded, fast moving freeway with a short on ramp in EV mode. Thought I was going to get rear ended by a semi. Wish I could change the default from EV to EV Auto.