When I used to add new tilesets to the the tile palette it would look fine.
But now when I add them they look like this, they are still the correct art just spread out and it makes it a lot harder to work with, any idea on what I’m doing differently to have changed this format?
I’d say your Tilemap grid settings don’t match the tileset (sprite) size. Or it’s the pixels per unit setting of the sprites.
Anyway, check the Grid, the sprite import settings, and if you use it, the sprite atlas settings. One of these is off. Just play with the settings and see how that affects the palette.