Hi Sean, mng and everyone,
The app developers switched the gLTF model reading library, now the PNG worked.
But I will send the links of our models in sketchfab as requested.
If possible, I would like to ask some questions ... Does the GLTF format keep all information after it is configured? Like light, and other important settings.
We are using threejs.org/editor to configure and export the file in GLTF, and for testing we use gltf-viewer.donmccurdy.com/ where we just drag the file ready to get a true view of what will be inside our app.
I would like to know if there is any other editor that tells me and that it can be better too
model 1 sketchfab: https://sketchfab.com/models/9de80b54b02d4f72a7d35cf84e75b211
This model the PNG not worked in the new library.
model 2 sketchfab:
And on this model the PNG has worked. If you'd like to see, you can download this model in GLTF, just drop on site gltf-viewer.donmccurdy.com/ (remember you need drop the folder compacted).
And if you think to talk in another social media would be better, we can without problem.
Any doubt, i'm available.