I read on another forum a few years ago (think it was a VW Golf forum) that VW’s wipers and washers work in the same way - i.e. wipers start before the washers. Not sure if my VW’s the same; I’ll need check next time I use the wipers.
The general consensus seemed to be that VW (and presumably
Cupra and other VAG brands) don’t fit a non return valve in the in the tubing between the washer jets and the washer fluid reservoir; the possible rationale for not fitting one? - if a non return valve were to be fitted, washer fluid retained in the tubing by a non return valve might be susceptible to freezing at the washer jet end of the tubing in very cold weather.
I seem to remember it was suggested on that forum that pulling the wiper stalk quickly and then immediately releasing it would prime the washer fluid ready for screen washing without activating the wipers. A second ‘normal’ (longer) pull on the stalk would then result in the washer fluid and wipers being activated at the same time. I’ve not tried this but it might be testing out this method to see if it actually works.