Lots of things can affect the track. Your tracking window size, motion, compression, fg elements interfering.
First of all, make sure your tracker is not set to stabilization. I’ve seen that in the past. Set it to stabilize, go to do something, come back, decide to track a shot, and nothing tracks, because you are not actually on the tracker.
Try tracking a smaller item in the shot…a shirt pocket, or collar, or belt buckle. Once the track is done, then expand the size of the shape to the whole item you wanted to track. This can help with edges getting interfered with if you window is too large.
And, as Marc said, be prepared to do some manual adjustment. (except for the world of tutorials) Tracks are not always perfect out of the gate. Learn to use the keyframe function to get over those stubborn areas.
Having to do some manual adjustment doesn’t mean your track didn’t work…it may mean you did it properly.
Glenn