If you use microsprays in your garden beds then they will get blocked.
Its inevitable as they have very small openings and it only takes a little grit or dirt to clog them up.
The fix is easy. Just unscrew the nozzle, get a needleor piece of wire and use the needle to clean the jet out. If you push it through the hole then you will remove the blockage and can then keep using the nozzle.
Alternatively you can just buy a new nozzle for around $1.00!