I've followed the thread, but it's always uncomfortable to suggest particulars in cases like these. As Lee and others have said, there are unlimited variations. However,
"Possibilities are an incorrect quality in the contact between my arm and the opponent's, insufficient circularity of movement,"
From some of your earlier descriptions of your problem, it seems you may be "seeking" a bit too much for the proper placement of your hands. Well, it seems, that may be because you're trying to apply a specific technique. In general, the classic advice for solving problems (particularly of defense) is to "adjust the legs and waist." However, imho, in this case, I would add "ignoring the near in seeking the far." My suggestion would be to avoid worrying about what you don't "get", but what can be accomplished with what you do "get."