Ive had this
problem on my arosa.
I have tried literally everything.
Vinegar, newspaper, glass cleaners of various types, fairy liquid, new wiper blades etc.
I finally had enough of it as it was getting so bad they would damage the motor befor elong as they seemed to be sticking to the screen, only the screen felt really smooth.
SO i thought, maybe its too clean, so in a last ditch attempt i sprayed on a bit of turtlewas wet look tyre dressing (to add grease to the screen!), cleaned that off with autoglym glass polish and then cleaned the wipers with autogylm rubber care and they seem fine now.
Although its not rained that much since, so time will tell.