There is a setting you must assign to a button if you want it to be like that.
The setting is "Cont/Inc Center Mode"
Unfortunately it defaults to Continuous. So that's why you must assign a button.
I and a few others have asked if this can be changed to default to Incremental but no joy yet.

That way if you would always want it in Incremental (which makes sense to me, the other dial does continuous)
you could save a button for a more useful function.
Greg