Could be that your numbers are down or just coiuld be the stage of the breeding cycle. I had the same trouble toms not answering or coming to the call just too many hens that they were with . I did the same thing figured out their pattern and ambushed em lol
At home right now I'm having the same trouble and it was the same last year I figure in another week or so they will have less hens and might want to come in to the call more.