Official dealers state that this is a constructive feature of the model. The problem can be fixed by installing a non-return valve in the washer tube, for example, Toyota. The valve code from Toyota is 85321-26020. He's cutting into the trout-line, namely, the fracking of the corrugated tube, before the injectors on the right, between the bonnet and the right front wing. The non-return valve prevents the outflow of liquid from the washer.