G1itch

I don't know if it's just me or the others have the same problem as mine, my first flight with a320neo was great, there's no performance issue, no significant FPS drop, but the next day( which is yesterday) when I wanna start another flight (By then my GPU utilization is almost 99%), after about couple min when i switch the elctric system on and importing the flight plan, my performance drop to about 5~10 FPS. However when I restart the flight, everything is back to normal, but the issue will appear after couple min. I do believe i have a decent PC spec. Note, I have turn all the AI traffic off and no GSX used.