Dudley side entry fill valve causing leak?

[dbrb2]

I have a Dudley side entry fill valve on y cistern.
It seemed to be working fine - but I noticed a small drip when it was filling.

On investigating, it looks like whilst some of the water is coming out the transparent plastic pipe as I would expect, a lot of it is coming out the back of the fill valve - where some of it is then splashing over the lid of the cistern.

The video below (assuming posting links like this works....) shows this. Before I look at replacing the valve entirely, is there any obvious reason/fix that would explain this?

New video by Ben Barker

photos.app.goo.gl

 

[terryplumb]

Not worth faffing about with ,fit a replacement.

 

[dbrb2]

I suspected as much. Just wanted to be sure it wasn't missing something obvioud