By default, the values of the sliders are set to come up with whatever values that were there the last time you were in NEW mode.
For example, in your case, open the tool and you see Sat = -14. WITHOUT CLICKING IN THE IMAGE (so you remain in NEW mode), change Sat = 0. Close the tool. Open it again, and you will see that Sat is still 0.
In the opposing scenario, you open the tool as above, and again Sat = -14. CLICK ON THE IMAGE SOMEWHERE (changing the mode to EDIT). Now change Sat to 0. Close tool. Open it again. Sat has gone back to -14, because you were in EDIT rather than NEW mode when you changed it to 0.
In summary, if you make any changes in NEW mode to the sliders (before applying them in EDIT mode), they will become the new defaults. I suppose this is useful in some situations. For me it's usually an annoyance. If there is a way to change this default behavior, I don't know where it is.