NN81 sorry my mistake
nevermind, I think it's more important to understand the mechanics of the problem.
The verification condition "on the floor" was missing because the first frame of the "walk" animation was diffrent size of the others, so different size with same origin point make a looping condition at object positioning "on the floor" - "not on the floor" that cause the issue. To make it simple, the problem could also be solved simply resizing and stretching the frame at 16x30pixel into 16x32
Without making any other changes at image points or collision boxes.