I’d start checking the diffuse and specular (metallic and shininess) channels, if the settings match the ones in Maya.
And also if any required textures are correctly referenced in the PlayCanvas materials. If not, you will have to upload and set them in place.
For shininess I am not sure if Maya uses that or roughness. In any case it’s the same just inverted.
So if you have 75 roughness in Maya, that translates approximately to 25 shininess in PlayCanvas for PBR lighting.
To see the same reflections, which seem to be all over the place in the Maya version hence the nice looks, you should definitely setup the same cubemap.
We were able to apply the cubemap to the model to some extent. Still waiting on the results with the final cubemap, but it seems to be working much better now! Thanks @Leonidas!