I’ve had an issue with leaking washer fluid on an ‘08 Astra XE. Crawled underneath to see where the fluid is leaking, I’ve seen other owners mention that the hose could come loose off the reservoir. The hose was attached, I pushed on it to fit more snugly to the pump and it started leaking more fluid than before. I’ll attach a photo I took of the location of the leak. Not sure if the pump is what’s leaking or the hose/connector. After pushing on the hose, the leak is now also dripping off the white piece on the bottom of the pump.

 

I would replace the pump, it will probably fall apart in your hands as you remove it.

 

You can ask someone to use pump while your looking to see exactly where leaking from. The picture looks like the left side hose connector, is the culprit, rubber or plastic inside the hose can definitely loosen overtime and from different temperature. Maybe it can be sealed ?