I have had washer jet nozzles clog more than once due to some kind of growth forming in the water. Maybe due to me using cheap screenwash and the vehicle getting very little use.
On mine the slime lodged inside the screen nozzle. I pulled the nozzle off and used an airline to blow back through it and cleared the gunk. I then cleared the washer bottle, put some water in and operated it with the nozzle off to check flow and that was ok. Put it back on and it worked OK.
I had a new bottle of the cheaper screenwash which I had had for quite a few months. The bottle was unopened and when I looked you could see some kind of growth forming inside. I am not sure if more expensive screenwash is any better, but this certainly put me off the budget end stuff!