Opacity mask not cutting off immediatley

Hi

Strange problem. I just migrated my assets to a new project to “clean out my messy files”. But have a strange situation in this new project with my opacity masks.

They seem to be not masking properly and giving a “fall off” transparancy effect before the invisible bits go totally invisible.

Example

As you can see, the ground is gradualy faing out instead of being a nice clean cut from texture to no texture.

255835-settings.png

This has happened on all my opacity mask textures so I am thinking it could be some global rendering setting maybe. I was under the impression that masks were a binary thing either on or off, so this has me stumped. Any suggestions?

TL:DR My opacity masks are fading out rather than being a clean cut from texture to no texture, why could this be?

NOTE - This does not happen in my old project, the materials act as they should.

Thanks in advance