Welcome to OG and congrats. It could have been any reason that he began to turn and walk away. Remember, we are trying to reverse nature. The hens want to breed and he struts and gobbles to let her know that he is there. She is supposed to go to him.
Ex: I firmly believe that sometimes decoys don't help us sometimes for this reason. Watch a mature Tom strut in fields and a lot of the time, he doesn't like to budge to come to a lone hen decoy and especially if he has other hens with him. Have had them skirt decoys just out of range many times. Just my opinion and one of the many different reasons why he turned to walk out of range.
Again, good job on the bird and welcome to OG.
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