Sounds like the main hose is being pinched somewhere, or your check valve has failed.

Start at the reservoir and inspect the hose.

The check valve looks like a black plastic T with a red cap on one side.

Pry the red cap off - do it somewhere where you will not lose the spring inside - some people do this on a table with a towel covering the process.

Inside the check valve there should be a small coil spring and a rubber valve that looks like a disc.

The disc can tear or turn to goo (caused by solvent in your washer fluid)..

If the disc tears, the fluid drains back to the reservoir when you stop washing. If the disc turns to goo, it can block the valve.

It is easy to make a new disc out of a small bit of a dishwashing glove (so small that your wife won't even notice it)

If you have to, disconnect the hose at each connection, starting at the reservoir to see if fluid comes out.

Newer cars have a filter also.