2D IK solver stops influencing sprite. Help

Hello,
I have a problem with 2D Limb Solver. I made an animation with it and it works fine. In editor when I am running animations it works without issues. However when I run the game (in editor or build) than SOMETIMES the bone which is attached to IK solver target stops influencing sprite which it should control.

Here is how it looks when it works properly


and here is when it does not work. Notice how the bone is correctly following the IK target but the sprite is ignoring the bone!



Anyone has any idea why is this happening? The most frustrating thing is that on some instances of a same prefab it is working correctly and on some it wont. Then it stops working and starts again......very annoying and I am not sure what is going on here.

 

looping GIF

 

Just to clarify. It is possible to just copy&paste same prefab multiple times and at some of the instances it is ok but others have problems described above. No changes. Just "CTRL+D" to duplicate them and they are not behaving same!

 

I just find out that if you enable/disable the defective sprite while the game is running it gets fixed.... But this is not the solution, only some strange workaround...