Why is my height map not displaying correctly

That is not app installation issue.The issue you're seeing with the height map not behaving correctly on a plane compared to a shirt mesh probably stems from how Sampler interprets surface geometry and material projection. Try this solutions.

1. Projection Settings

• For the plane, make sure you’re using UV Projection (not Triplanar) if the UVs are well laid out.
• If the plane doesn’t have proper UVs, switch to Triplanar Projection to auto-fit the material, which often handles flat surfaces better.

2. Height Map Behavior

• Go to the Material Properties → Height Channel, and verify the intensity and scale.
• On flat geometry, height maps may appear muted unless you boost displacement or parallax settings under the viewer's rendering options.

3. Tiling and UV Scaling

• The shirt mesh might have finer tiling due to its UV density. Try increasing the tiling on the plane’s material to match the shirt’s visual detail.

4. Geometry Density

• If your plane is a simple quad. If you're using height-as-displacement, add subdivisions via your mesh settings in Sampler or externally before import. Otherwise, use the height map as bump/parallax only.

5. Rendering Preview Settings

• Make sure Parallax Occlusion Mapping or Displacement Preview is enabled under the 3D viewport settings. Height map differences might not show up unless these are active.