Losing Materials Blender 2.80 to GLTF 2.0 export using Khronos Group Add On

I am exporting models from Bender 2.8 to GLTF 2.0 and losing materials that I worked hard on to get right in Blender. What is the next step for me to try? Redo stuff with GLTF shaders from Khronos group?

Thanks.

John