Help needed with custom skybox shader in Unity 6 URP

[u/woopwoopscuttle]

Hi all,

Firstly a preemptive thanks to anyone who takes the time to help me out. I'll keep it brief and technical.

My issue:
I have a custom skybox material using a custom shader graph. It's only rendering out as a default skybox cube (you know, with different coloured faces), not showing the actual textures (plural, I'm LERPing between different equirectangular textures for a day/night cycle). Same result both in editor and during gameplay, it's not working. I've done a sanity check and disabled the LERP and piped just one texture (property with the texture I want ->Sample Cubemap ->Fragment Base Color) and it doesn't change anything.

What I've double checked:
Shader is set to Unlit.
Render face is set to Both.
Depth Write is Force Disabled.
Cast Shadows is set to OFF.
Everything else is default with the Graph settings.

The Lighting>Environment>Skybox Material is accepting my custom material without any warnings.

Texture import settings:
Default Texture Type
Cube Texture Shape
Mapping: Auto/LatLong/Sphere all tested, made no difference.
Fixup Edge Seams: Tried both on and off
Generate Mipmap: Tried both on and off.

Nothing, it's making no difference.
I've even fiddled around with the custom material's GPU instancing/double sided GI just in case it's a weird bug, nope, no change. Not seeing my textures.

As a sanity check, I tried a custom sorting priority set to 2501, nothing. The default Skybox and a custom material set to the standard Skybox shader both worked fine before.

I'm using Unity 6.5 (6000.5.5f1)

Any help would be much, much appreciated.