The barrel inside should have three tiny holes. Early ones the barrel was prone to coming loose and rotating a little, hiding the holes, or moving sideways out of the housing, leaving a dribble instead of a squirt.
Have a good look at it to see if the barrel is out of place. There's a screwdriver slot on the side for adjusting it, but rotating it far may make it loose. New ones are not expensive.
If the barrel will rotate and stay tight enough, turn it 180 degrees. The tiny holes outside usually have larger ones inside, where the goo collects. Turning the big holes out, then giving a squirt will often eject the goo. Then turn them back again and spend an hour adjusting them. Once happy, drive off, and find they are too low when moving. Adjust up a bit, and squirt over the roof. Always been a problem with almost every car since washers were created.