With digital signals you need to "see" the signal with your batwing BEFORE you do the scan on the TV, If the batwing angle is off the TV will not find anything. Not like the old days where you could find a fuzzy signal and then rotate the batwing to improve it. With digital it either sees a signal to it does not - no in between.
I use this
Sure Lock digital signal finder.
I leave it connected to one of the unused TV outlet on the distribution box, turn it on and let it hang out of the cabinet where I can see it from upstairs, then rotate the batwing until it has a strong signal. THEN I use the search function on the TV. Works every time.
Sometimes you will get good signals in a couple of directions and might need to turn the batwing and re-scan to get other stations.