Same problem for me. I can hear it whining
Had an MOT today, thought it would fail so I did one side this morning using a paper clip, poking it into the two holes of the washer jet
I tried it again, then after a minute some black gunk came out of the jet & now it's working 100%
Tried to do the other side at kwik fit while waiting for the MOT & the not tester came over & asked what I was doing & said leave it, I won't fail you on that
I'm gonna try the other side now