Keeping an image or object the same size regardless of distance?

I’m having SEVERE difficulty trying to stop my background HDRI or even background static meshes from resizing as the player gets closer or further way from them.

Here’s what I mean:

When the players is some distance away we get this you can see the edges of the mountain in the red circle.

But when we move close up to the wall and closer to the mountain the edges are gone:

How do I stop this rescaling from happening?

I’ve tried using a skysphere hdri image but it doesn’t work either it still has this resizing issue!!!

It’s just sinking behind your floor plane, lol

No its not, its something called parallax thats designed into most 3d games, so the closer you get to something the larger it gets to aid realism, but I need to switch this off for the background