a friends 1st round of yb,s one flys the other does not so the one that does not fly killed. 2nd round one flys one does not it wont fly up to perch or up to drinker.so he has been lifting yb up to drinker.now that yb is a bit older it is taken 20 yards back from loft and hand opened it flys back in to loft .still wont fly up to drinker or perch . so i am a bit puzzled any ideas.