It can come as a result of faulty hybrid cell. You will need to replace them you'll notice that when you reset the car the hybrid system will turn on. This means that a section of the cells are faulty not all of them. If it doesn't turn on it means all the cells need replacement which is rare.
Halo mine didn't. the petrol engine is working fine I got the cells replaced for the electric engine. You can check your plugs first they could the cause of loss in powe