fear not, its the beans.
Most people wouldnt experience this because they stick to the same blend all the time.
but people that have a special interest in coffee like to chop and change, and sometimes they end up with a blend or type of beans thats quite different from the last lot they used..ergo, the "problem" you just experienced...only its not a problem, its the way it is.
Dont worry about the number settings on the adjuster. I dont ever look at them. Just find the right grind for the coffee in use, and be prepared for a change when you select another type of coffee.