I am fairly new to unity and I have encountered this same problem previously.
I have a gun with hands and I created an animation that simulates shot movements with properties
transform.rotation. Root motion is applied and motion curves are generated for the animation.The default state animation for that object has no properties assigned to it and as much as I understand from the animation controller window, the shot animation is completed before the transition to the default state is made.
The problem is that on every 3 shots 0.001 is added to the X rotation; Y and Z positions are losing some small values.
I tried to prolong the animations exit time but the result is the same. I checked the key values and the motion curves, the first and last ones are the same. Why is this happening and how can I fix it ?