It probably should be, but it really doesn't make any difference that it's not. It is not the time that gives you your 'medium rare' but your temperature. The timer on the unit and app are just a courtesy inclusion. They don't actually do anything other than make the unit beep incessantly. Time is flexible with sous vide processing. You will notice little difference in your steak should you cook it for an hour or for 2 hours or even 3.
It will get more tender with longer cooking as more of the collagen in the steak will convert to gelatin.
With an inch thick steak you will need to be very careful and quick when searing it so as not to force it beyond your perfect medium rare.