Thank you for a reasoned reply. If the energy is not conserved the device is acquiring energy by some process not yet understood. There is always an explanation.
It’s not the energy at issue but conservation of momentum. Laser light can have awesome energy but little momentum to transfer—2 gigawatt laser could levitate a squirrel riding a perfect mirror, based on the recoil momentum of reflected photons. A good cherry bomb under a garbage can lid could transfer more momentum.