Decal projector when affecting normal seems to be broken when using surface gradient

Repro steps :

• Open attached project
• Open scene called "Outside"
• Select the decal and move its opacity
• Do it on the Plane and on the Ocean separetely

Expected : Nothing should change
Result : The result change slightly on the water and when Additive decal blending on classic geometry

Additional info :

• The normal used is uncompressed neutral normal 127/127/255
• Result is different on Normal geometry when using Additive blending (So probably linked to surface gradient)
• Need to check if repro in older versions

Environment :

• Windows 10
• Unity 2023.1.0a26
• HDRP 15.0.3