Textures not correct on the SketchFab display

As you can see, the textures do not really work when i try do uploud the model on Sketchfab. Any idea? i embemded the textures on the fbx model because i could not make it work otherwise.
Thanks in advance.

Perhaps , it is a problem with the light ?

i tested the light, is not that. is kind of a weird problem, cause some part of the texture is inside out. i think this image may help what im trying to say. Thanks for your response. Any ideas what could be happening? Some problem with the UV? Is just a Sketchfab problem, cause in any other software, everything is fine.

Yes , it is very strange . Perhaps it is a problem with the normals if you have many surfaces and textures ?

Maybe, you know anything that could help? I tried to change the mesh it self with a modifier in blender to see if that could help (i saw this in another problem on the forum, a bit different tho), no luck there.

nevermind, it was the light like you said ahahah
Thanks man.