Nearly always when we get a question like this it is due to a misconfiguration of the scoring "ranges."
Typically, the scoring ranges have been set up something like this:
0.000-49.000 = 10.500-99.000 = 2 In this example, if a player is projected to have say, 49.5 yards they would fall outside of any range and be awarded 0 points. This causes scoring anomolies for a select few players, depending on their exact projections data. The solution is to update your ranges in the scoring rules for your league to close the gaps in ranges. (eg. 0.000-49.999).