700 Class gas engine helicopter tail wave

Hi,
I use a 700 class gasline heli in poshold mode but the tail is always wave, you could see in log


and I used governor to keep the rotor speed but have some shake

I’m not sure it may cause the tail wave
It is very appreciate if anyone could give some suggest
the log attached
https://drive.google.com/file/d/1Vfc4XQcy-ZKxhtjIaOK-8DjZEVi4nHfT/view?usp=sharing