Yes, that is normal and caused by softness. The bones slow down as they near the target, so the target needs to be moved a bit farther to get the bones all the way straight. You may need to edit animations to move the target farther. However, try using the smallest softness distance that makes your bones not snap as they straighten. With a small softness distance, maybe you won't be able to see that the bones don't straighten all the way.