I just changed twie of wipers 60 euros spent and both do not clean the windshield at all, I spray a whole container of liquid wash nothing, I wnet to bmw to buy news ones, identical , they do not clean the windshield at all!!!

 

spray some PB Blaster on the pivot points on the wiper arms. mine did the same thing, and a shot of pb fixed it. also, check the blade,it may need replaced