You allready know the problem . The things you have stated are big problems . Mathews cams need to be indexed corectly to get good arrow flight . Line up the cam the way it should be by twisting or untwisting the cabel and or string . I would try to get them both as close to what the factory recomends before puting them on the bow . A mathews cam out of index will give bad nock travel , and the type of arrow flight you are getting . A mathews cam indexed correctly will give you good nock travel . I think there was more truth to their adds the last couple years than some would like to admit . Another word of advise , ditch the trapdoor . They dont work very well with singlecam bows IMO as you need a rest that gives alittel more suport . The trapdoors fall away very quickly .