Right. This sounds like a classic case of excessive preload. The issue is not the amount of torque you're putting into the crank bolt. That is designed to hit a hard stop, thus making the width of the crank fixed. The issue is that either your BB shell is slightly too wide for your cranks or there are too many preload washers.
Also: every bearing will feel "notchy" if excessively preloaded. This is called binding.