The local dealer had never heard of this problem!
But replaced the drivers wiper under warranty for a "new" style blade . The new blade doesn't lift off at such a low speed 50-60, but still does not clear the screen when over 80mph.
Dealer is going to inverstigate at 12,000 service next week. IMO it is either the wiper arm spring tension or the blade length and aerofoil section not being attuned. If said dealer cannot fix problem I will go with a smaller bosch wiper which has an aerofoil £12 from Halfrauds.
The clips to attach the washer tubing can be purchased from Alfa only as part of the tubing assembly which retails at £6 +vat