Art not always fading to grey

I've had this issue for a while, and I think when I brought it up before it was concluded nothing could be done about it but I thought I'd ask again.

Sometimes slave art fades between black and grey, and sometimes it does not. When it does not, the way it runs into the text is very noticeable.

The way it should look:

The problem:

No idea what triggers it or how it could be fixed, but I thought I'd ask.

no_grey.save