what's your weather? The gold standard for alignment is a DirecTV AIM meter. Not something that most of us have. Calling DirecTV for a truck roll will get that. What I use for a SWM LNB is a cheap analog signal meter and a splitter that forces reception of only 101 and provides 18V DC to the LNB, DirecTV used that when they first introduced SWM LNBs. You then have to go through a process called "dithering". You count the the number of turns of the adjustment screw between two points left and right of center where the signal strength is for example 75% of what it is at the peak, then center the dish between those two points. You do that first for elevation, then for azimuth. If your skew is set properly, 119 should come in. If you are dead center on 101, 99 and 103 will come in. But you can't just tune for the peak on 101, because the SWM LNB has Automatic Gain control, which creates a broad, flat peak. It is possible, I'm told, to use the signal meter on the STB, but you need a helper.
When my dish has gone out of alignment it usually has been the elevation adjustment.