1) Open any HDRP project
2) Create an empty game object and move it away from 0,0,0 coordinates
3) Right click the object above and add a cube or point light
4) Notice the new object spawns at 0,0,0 local coordinates
5) Now right click parent again and add a decal
6) Notice it ignores the child spawn logic and does not spawn at local 0,0,0 coordinates

Expected: When adding a decal as child object. It should spawn the same way other unity objects do (lights, geometry etc).

Easiest to understand looking at the video. Everything I add spawns in the correct location, except decals.