Weird SRAM NX derailleur

My changing was off recently so I figured it was the fact I was on my third chain and everything was just worn out.

Replaced the cassette, front sprocket, and chain, however, the shifting is still off. It won't shift from the second smallest cog onto the smallest, and then shifts weird going up.

I've examined the derailleur and it seems that the part of the derailleur where the cable goes into is somehow preventing the clutch/thing which moves up and down the cassette from moving down fully to allow the chain to sit on the smallest cog. Also, its resulting in rub on the cable and is consequently fraying it.

Does anyone of this sound familiar? It's quite hard to describe, perhaps I should post a picture.

Advice welcome (should it be replaced too?)