Bug Animation Causes Extremely High Editor Loop?

a very strange thing happens to me.
I have an animator and some animations on it, I found that if I use "always animate" on the animator, there will be extremely high editor loop when in play mode.
It seems causes by some animation state, but i can't find any special things on those animation.
Standalone profiler shows the editor loop is up to 600ms

my unity version is 2020.3.40f1c1，and I also tried 2021.3.13f1c1，it's the same

 

I've found something in profiler, but anyone knows what's this and what causes this?