Problem with imported object rotation

Hi, Guys. I have some issue with object rotation. 1. imported object from Blender and get XYZ(270,0,0). 2.created prefab and drag-drop my object and get XYZ(-90,0,0) 3. change X in 0. And prefab XYZ (0,0,0);

And then I try rotate it such as:

transform.localRotation = Quaternion.Euler( transform.localEulerAngles.x + 10 ,0,0);

but every frame my object reverse into old X. In runtime I have X = 270 or 280. 270->280->270->280....

But when I change rotate axis Y or Z :

Y - transform.localRotation = Quaternion.Euler( 0,transform.localEulerAngles.y + 10 ,0); Z - transform.localRotation = Quaternion.Euler( 0,0,transform.localEulerAngles.z +10);

I have nice smooth rotate. What I can do something wrong