Repro:

Download the attached repro project: here
Open the Scene "TerrainSceneViewBug"
From (Windows > Rendering > Lighting) click Generate Lighting to update lightmaps
Click the Terrain GameObject in the Hierarchy
From the Terrain's Inspector, select the "cog with mountain" icon to see the terrain settings
Note that the Legacy Terrain material is assigned
From the Scene View modes menu, change to "Baked Lightmaps"  
You may need to change the Lightmap Exposure (bottom right on Scene view) and deselect the terrain to see the lightmaps correctly
Observe that the checkerboard overlay appears as expected and the lighting is correctly mapped to the terrain object
Navigating back to the Terrain GameObject, from Terrain Settings, now assign the material "DefaultHDTerrainMaterial"

Observed:

See that the UVs for the terrain lightmaps appear to be scaled/offset incorrectly when using the HDRP Terrain material

Expected:

HDRP/TerrainLit should use the same UV coordinates as the legacy terrain shader. This issue makes debugging baked terrain lighting almost impossible.